Hosoya polynomial of small trees

23
ZBORNIK RADOVA Prirodno–matematiˇ ckog fakulteta u Kragujevcu, 21 (1999) 111–119. COLLECTION OF SCIENTIFIC PAPERS of the Faculty of Science Kragujevac, 21 (1999) 111–119. HOSOYA POLYNOMIALS OF TREES WITH UP TO 11 VERTICES Dragan Stevanovi´ c a and Ivan Gutman b a Faculty of Philosophy, ´ Cirila i Metodija 2, 18000 Niˇ s, Yugoslavia, and b Faculty of Science, P. O. Box 60, 34000 Kragujevac, Yugoslavia (Received March 7, 1999) Abstract. Let G be a connected graph. If d(G, k) is the number of pairs of vertices of G that are at distance k apart, then k0 d(G, k) x k is called the Hosoya polynomial of G . The Hosoya polynomials of all trees with 11 or less vertices (1 + 1 + 1 + 2 + 3 + 6 + 11 + 23 + 47 + 106 + 235 trees) are tabulated. INTRODUCTION The polynomial H (G, x) , which originally was called “Wiener polynomial ”, but which eventually was re-named into “Hosoya polynomial ”, was invented by Hosoya in 1988 [1] as a counting polynomial of potential interest in mathematical chemistry. The first works devoted to the study of its properties appeared in 1993 and 1994 [2]–[4], whereas an extensive research along these lines started relatively recently [5]–[9]. Most examinations of H (G, x), especially the recent ones [5, 6, 9], are concerned with the case when G is a tree. In view of this, it would be advantageous to possess tables of the Hosoya polynomials of trees. By means of them properties H (G, x) could be better envisaged, and various conjectures could be checked (and counterexamples for them found). In the published, both mathematical and chemical literature, such tables are not available. Our aim here is to fill this gap. Let G be a connected graph of order n . Let d(G, k) be the number of pairs of vertices of G that are distance k apart, k =1, 2,... . In addition to this, d(G, 0) is equal to the number of vertices of G , i. e., d(G, 0) = n . Then the Hosoya polynomial of G is defined as [1], H (G)= H (G, x)= D k=0 d(G, k) x k

description

Hosoya polynomial of small trees

Transcript of Hosoya polynomial of small trees

Page 1: Hosoya polynomial of small trees

ZBORNIK RADOVA Prirodno–matematickog fakulteta

u Kragujevcu, 21 (1999) 111–119.

COLLECTION OF SCIENTIFIC PAPERS of the Faculty

of Science Kragujevac, 21 (1999) 111–119.

HOSOYA POLYNOMIALS OF TREES WITH UP TO 11 VERTICES

Dragan Stevanovica and Ivan Gutmanb

aFaculty of Philosophy, Cirila i Metodija 2, 18000 Nis, Yugoslavia, andbFaculty of Science, P. O. Box 60, 34000 Kragujevac, Yugoslavia

(Received March 7, 1999)

Abstract. Let G be a connected graph. If d(G, k) is the number of pairs of vertices of G that are at

distance k apart, then∑

k≥0d(G,k) xk is called the Hosoya polynomial of G . The Hosoya polynomials of

all trees with 11 or less vertices (1 + 1 + 1 + 2 + 3 + 6 + 11 + 23 + 47 + 106 + 235 trees) are tabulated.

INTRODUCTION

The polynomial H(G, x) , which originally was called “Wiener polynomial”, but which eventually

was re-named into “Hosoya polynomial”, was invented by Hosoya in 1988 [1] as a counting polynomial

of potential interest in mathematical chemistry. The first works devoted to the study of its properties

appeared in 1993 and 1994 [2]–[4], whereas an extensive research along these lines started relatively

recently [5]–[9]. Most examinations of H(G, x), especially the recent ones [5, 6, 9], are concerned

with the case when G is a tree. In view of this, it would be advantageous to possess tables of the

Hosoya polynomials of trees. By means of them properties H(G, x) could be better envisaged, and

various conjectures could be checked (and counterexamples for them found). In the published, both

mathematical and chemical literature, such tables are not available. Our aim here is to fill this gap.

Let G be a connected graph of order n . Let d(G, k) be the number of pairs of vertices of G that

are distance k apart, k = 1, 2, . . . . In addition to this, d(G, 0) is equal to the number of vertices of

G , i. e., d(G, 0) = n . Then the Hosoya polynomial of G is defined as [1],

H(G) = H(G, x) =

D∑

k=0

d(G, k)xk

Page 2: Hosoya polynomial of small trees

where D = D(G) is the diameter of the graph G , i. e., the greatest distance between two vertices

of G .

It should be noted that sometimes the Hosoya polynomial is defined in a slightly different manner,

namely as∑

k≥1d(G, k)xk . Even in this case the constant term d(G, 0) is fully determined: because

of the identityD∑

k≥1

d(G, k) =

(

n

2

)

d(G, 0) can be calculated from d(G, 1), d(G, 2), . . . , d(G,D) .

The most remarkable property of the Hosoya polynomial is that its first derivative at x = 1 is

equal to the sum of the distances between all pairs of vertices of G , which is just the well–known

and much studied Wiener index, a graph invariant possessing numerous chemical applications. (This

fact was obviously the reason why Hosoya called H(G, x) “Wiener polynomial”.) Recently also the

higher derivatives of H(G, x) at x = 1 found applications in physical chemistry and pharmacology

[10].

THE TABLE

The table of Hosoya polynomials of trees is organized in the following manner. The trees are

grouped according to the number (n) of vertices, n = 1, 2, . . . , 11 . Within each group of trees with

a fixed number of vertices, the trees are ordered lexicographically with regard to the coefficients

d(G, k) , k = 0, 1, 2, ..., D(G) of the Hosoya polynomial; of course, for all such trees d(G, 0) = n and

d(G, 1) = n− 1 . The Hosoya polynomial is given below the picture of each tree.

Page 3: Hosoya polynomial of small trees

1 tree with 1 vertex: 1 tree with 2 vertices: 1 tree with 3 vertices:

r

1

r r

x+2

r rr

x2+2x+3

2 trees with 4 vertices:

r rr r

x3+2x2+3x+4

r

r rr

3x2+3x+4

3 trees with 5 vertices:

r rr rr

x4+2x3+3x2+4x+5

r r

r

r r

2x3+4x2+4x+5

r r

r rr

6x2+4x+5

6 trees with 6 vertices:

r rr rrr

x5+2x4+3x3+4x2+5x+6

r

r rr rr

2x4+3x3+5x2+5x+6

r

r rr rr

x4+4x3+5x2+5x+6

rr

r rrr

4x3+6x2+5x+6

r r

r r

r r

3x3+7x2+5x+6

r r r

r rr

10x2+5x+6

11 trees with 7 vertices:

r rr rrr r

x6+2x5+3x4+4x3+5x2+6x+7

r

r rr rrr

2x5+3x4+4x3+6x2+6x+7

r

r rr r rr

x5+3x4+5x3+6x2+6x+7

rr

r rr rr

4x4+4x3+7x2+6x+7

r

r r

r

r rr

3x4+6x3+6x2+6x+7

r r

r rr rr

3x4+4x3+8x2+6x+7

r

r

r

r

r r r

2x4+6x3+7x2+6x+7

r r

r rr rr

x4+6x3+8x2+6x+7

r

r r

r r

r r

6x3+9x2+6x+7

r r

r r r

r r

4x3+11x2+6x+7

r r r r

r rr

15x2+6x+7

23 trees with 8 vertices:

r rr rrr r r

x7+2x6+3x5+4x4+5x3+6x2+7x+8

r

r rr rrrr

2x6+3x5+4x4+5x3+7x2+7x+8

Page 4: Hosoya polynomial of small trees

r

r rr r rrr

x6+3x5+4x4+6x3+7x2+7x+8

r

r rrrr rr

x6+2x5+5x4+6x3+7x2+7x+8

rr

r rr r rr

4x5+4x4+5x3+8x2+7x+8

r r

r rr rrr

3x5+4x4+5x3+9x2+7x+8

r

r r

r

r r rr

2x5+5x4+7x3+7x2+7x+8

r

r r

rr rr r

2x5+5x4+6x3+8x2+7x+8

r

r r

rr rr r

2x5+4x4+7x3+8x2+7x+8

r r

r rrr r r

x5+4x4+8x3+8x2+7x+8

r r

r rr r rr

x5+4x4+7x3+9x2+7x+8

r

r r

r r

rr r

6x4+5x3+10x2+7x+8

r r

r rr r

r

r

5x4+8x3+8x2+7x+8

r rr

r rrr r

4x4+8x3+9x2+7x+8

r r r

r rr rr

4x4+5x3+12x2+7x+8

r

r

r r

r

r rr

3x4+9x3+9x2+7x+8

r

r

r

r r

r r r

3x4+8x3+10x2+7x+8

r r

rr r

r rr

2x4+9x3+10x2+7x+8

r r r

r rr rr

x4+8x3+12x2+7x+8

rr r

r r

r

rr

9x3+12x2+7x+8

r

r r

r r r

r r

8x3+13x2+7x+8

r r

r r r r

r r

5x3+16x2+7x+8

r r r r r

r rr

21x2+7x+8

47 trees with 9 vertices:

r rr rrr r rr

x8+2x7+3x6+4x5+5x4+6x3+7x2+8x+9

r

r rr rrr rr

2x7+3x6+4x5+5x4+6x3+8x2+8x+9

r

r rr r rrrr

x7+3x6+4x5+5x4+7x3+8x2+8x+9

r

r rrr r rr r

x7+2x6+4x5+6x4+7x3+8x2+8x+9

rr

r rr rr rr

4x6+4x5+5x4+6x3+9x2+8x+9

r r

r rr rrrr

3x6+4x5+5x4+6x3+10x2+8x+9

r

r r

rrr rr r

2x6+5x5+5x4+7x3+9x2+8x+9

r

r r

r

r r rrr

2x6+4x5+6x4+8x3+8x2+8x+9

Page 5: Hosoya polynomial of small trees

r

r r

rr rrr r

2x6+4x5+5x4+8x3+9x2+8x+9

r

r r

rr r rr r

2x6+3x5+7x4+7x3+9x2+8x+9

r

r r

r

rrr rr

x6+4x5+7x4+8x3+8x2+8x+9

r r

r rrr rr r

x6+4x5+6x4+8x3+9x2+8x+9

r r

r rr r rrr

x6+4x5+5x4+8x3+10x2+8x+9

r r

r rr r rr r

x6+3x5+6x4+9x3+9x2+8x+9

r r

r rrrr rr

x6+2x5+7x4+8x3+10x2+8x+9

r

r r

r r

r rr r

6x5+5x4+6x3+11x2+8x+9

r

r r

r

r r

r

r r

4x5+7x4+8x3+9x2+8x+9

r

r r

rr

rr rr

4x5+6x4+8x3+10x2+8x+9

r r r

r rr rrr

4x5+5x4+6x3+13x2+8x+9

r r

r rr r r

r

r

3x5+7x4+9x3+9x2+8x+9

rr r

r rr rrr

3x5+7x4+7x3+11x2+8x+9

rr r

r rr rrr

3x5+5x4+9x3+11x2+8x+9

r

r r

r

r r

r

r r

2x5+7x4+10x3+9x2+8x+9

r

r r r

rr rr r

2x5+7x4+8x3+11x2+8x+9

r

r r

r

r

r r r r

2x5+6x4+10x3+10x2+8x+9

r

r

r r

r

r r rr

2x5+6x4+10x3+10x2+8x+9

r

r r r

rr rr r

2x5+5x4+10x3+11x2+8x+9

rr r

r rrr rr

x5+5x4+11x3+11x2+8x+9

r r r

r rr r rr

x5+5x4+9x3+13x2+8x+9

rr r

r r

r

r rr

9x4+6x3+13x2+8x+9

r

rr

r r

r

r rr

8x4+10x3+10x2+8x+9

r

r r

r r r

rr r

8x4+6x3+14x2+8x+9

r r r

r rr rr

r

7x4+10x3+11x2+8x+9

r r

r r

r r

r rr

6x4+12x3+10x2+8x+9

Page 6: Hosoya polynomial of small trees

r r

r r

rr

r rr

6x4+10x3+12x2+8x+9

r r

r

r rr r

r

r

5x4+12x3+11x2+8x+9

r r r r

r rr rr

5x4+6x3+17x2+8x+9

r r rr

r rrr r

4x4+12x3+12x2+8x+9

r

r

r

r r r

r r r

4x4+10x3+14x2+8x+9

r r

r

r r

r

r rr

3x4+12x3+13x2+8x+9

r

r r

r

r r

r r r

3x4+12x3+13x2+8x+9

r r

rr r r

r rr

2x4+12x3+14x2+8x+9

r r r r

r rr rr

x4+10x3+17x2+8x+9

r r

r r

r r r

r r

12x3+16x2+8x+9

r

r r

r r r r

r r

10x3+18x2+8x+9

r r

r r r r r

r r

6x3+22x2+8x+9

r r r r r r

r rr

28x2+8x+9

106 trees with 10 vertices:

r rr rrr r rrr

x9+2x8+3x7+4x6+5x5+6x4+7x3+8x2+9x+10

r

r rr rrr r rr

2x8+3x7+4x6+5x5+6x4+7x3+9x2+9x+10

r

r rr r rr rrr

x8+3x7+4x6+5x5+6x4+8x3+9x2+9x+10

r

r rrr r rr rr

x8+2x7+4x6+5x5+7x4+8x3+9x2+9x+10

r

r rr rr rrr r

x8+2x7+3x6+6x5+7x4+8x3+9x2+9x+10

rr

r rr rrr rr

4x7+4x6+5x5+6x4+7x3+10x2+9x+10

r r

r rr rrr rr

3x7+4x6+5x5+6x4+7x3+11x2+9x+10

r

r r

rrr rrr r

2x7+5x6+5x5+6x4+8x3+10x2+9x+10

r

r r

r

r r rrrr

2x7+4x6+5x5+7x4+9x3+9x2+9x+10

r

r r

rr rrrr r

2x7+4x6+5x5+6x4+9x3+10x2+9x+10

r

r r

rr rr rr r

2x7+3x6+6x5+7x4+8x3+10x2+9x+10

r

r r

rr r rrr r

2x7+3x6+5x5+8x4+8x3+10x2+9x+10

r r

r rrr rrr r

x7+4x6+6x5+6x4+9x3+10x2+9x+10

r r

r rr r rrrr

x7+4x6+5x5+6x4+9x3+11x2+9x+10

Page 7: Hosoya polynomial of small trees

r

r r

r

rr r rr r

x7+3x6+6x5+8x4+9x3+9x2+9x+10

r r

r rrr r rr r

x7+3x6+5x5+8x4+9x3+10x2+9x+10

r r

r rr r rrr r

x7+3x6+5x5+7x4+10x3+10x2+9x+10

rr

r rrr r rrr

x7+2x6+5x5+8x4+10x3+10x2+9x+10

r r

r rrr r rr r

x7+2x6+5x5+8x4+9x3+11x2+9x+10

r

r r

r r

r rrr r

6x6+5x5+6x4+7x3+12x2+9x+10

r

r r

r

r

r

r rr r

4x6+6x5+7x4+9x3+10x2+9x+10

r

r r

r

r

r rr r r

4x6+6x5+6x4+9x3+11x2+9x+10

r r r

r rr rrrr

4x6+5x5+6x4+7x3+14x2+9x+10

r rr

r rr r rr r

4x6+4x5+9x4+8x3+11x2+9x+10

rr r

r rrrr rr

3x6+7x5+6x4+8x3+12x2+9x+10

r

r r

r

rr

r

r rr

3x6+6x5+9x4+9x3+9x2+9x+10

r r

r rr r rr

r

r

3x6+5x5+8x4+10x3+10x2+9x+10

rr r

r rr rrrr

3x6+5x5+6x4+10x3+12x2+9x+10

rr r

r rr r rrr

3x6+4x5+9x4+8x3+12x2+9x+10

r

r r r

rrr rr r

2x6+7x5+6x4+9x3+12x2+9x+10

r

r

r

rr

r

r rr r

2x6+6x5+9x4+9x3+10x2+9x+10

r

r r

r

rr r

r

r r

2x6+6x5+8x4+10x3+10x2+9x+10

r

r r r

rr rr r r

2x6+6x5+7x4+10x3+11x2+9x+10

r

r rr

rrrr r r

2x6+5x5+8x4+10x3+11x2+9x+10

Page 8: Hosoya polynomial of small trees

r

r

r r

r

r r rrr

2x6+5x5+7x4+11x3+11x2+9x+10

r

r r r

rr rrr r

2x6+5x5+6x4+11x3+12x2+9x+10

r

r

r r

r

r r rrr

2x6+4x5+9x4+11x3+10x2+9x+10

r

r

r r

rr rrr r

2x6+4x5+8x4+11x3+11x2+9x+10

r

r r r

rr r rr r

2x6+3x5+10x4+9x3+12x2+9x+10

r r

r rrrr r

r

r

x6+6x5+9x4+10x3+10x2+9x+10

r

r

r rr

r

r rr r

x6+5x5+9x4+11x3+10x2+9x+10

r r r

r rrr rr r

x6+5x5+8x4+10x3+12x2+9x+10

r r r

r rr r rrr

x6+5x5+6x4+10x3+14x2+9x+10

r

r

r r

r

rrr rr

x6+4x5+9x4+11x3+11x2+9x+10

rr r

r rrr rr r

x6+4x5+8x4+12x3+11x2+9x+10

rr r

r rr r rrr

x6+4x5+7x4+12x3+12x2+9x+10

r r r

r rr r rr r

x6+3x5+8x4+12x3+12x2+9x+10

r r r

r rrrr rr

x6+2x5+9x4+10x3+14x2+9x+10

rr r

r r

r

r r rr

9x5+6x4+7x3+14x2+9x+10

r

r r

r r r

r rr r

8x5+6x4+7x3+15x2+9x+10

r r

r

r rr r

r

r r

6x5+9x4+10x3+11x2+9x+10

r r

r r

r

r r

r

rr

6x5+9x4+9x3+12x2+9x+10

rr

r r

r r

rrr r

6x5+8x4+9x3+13x2+9x+10

r r

r r

rr

rr rr

6x5+7x4+10x3+13x2+9x+10

r r r r

r rr rrr

5x5+6x4+7x3+18x2+9x+10

r

r r

r

r

r

r

r r r

4x5+10x4+12x3+10x2+9x+10

r

r r

r rr rr

r

r

4x5+10x4+11x3+11x2+9x+10

Page 9: Hosoya polynomial of small trees

r

r r

r

r

r

r

rr r

4x5+9x4+12x3+11x2+9x+10

r

r r

r

r

r r

r

r r

4x5+9x4+11x3+12x2+9x+10

r r r

r rr r rr

r

4x5+9x4+11x3+12x2+9x+10

rr r r

r rr rrr

4x5+9x4+8x3+15x2+9x+10

rr

r r

rr

rr r r

4x5+8x4+12x3+12x2+9x+10

r

r r

rr r

rr rr

4x5+8x4+11x3+13x2+9x+10

rr r r

r rr rrr

4x5+6x4+11x3+15x2+9x+10

r r

r

r rrr

r

rr

3x5+10x4+12x3+11x2+9x+10

r

r r r r

rr rr r

3x5+10x4+9x3+14x2+9x+10

r r

r r

r r

r r rr

3x5+9x4+13x3+11x2+9x+10

r r

r

r rr r r

r

r

3x5+8x4+13x3+12x2+9x+10

r

r r

r

r r

r r r r

3x5+8x4+12x3+13x2+9x+10

r

r r r r

rr rr r

3x5+6x4+13x3+14x2+9x+10

r r

r r

r

r

r

r rr

2x5+9x4+13x3+12x2+9x+10

r

r r r r

rr rr r

2x5+9x4+10x3+15x2+9x+10

r r

r r

r

r r

r

r r

2x5+8x4+14x3+12x2+9x+10

r

r r

r

rr

r r rr

2x5+8x4+13x3+13x2+9x+10

r

r

r

rr r

r r rr

2x5+7x4+14x3+13x2+9x+10

r r

r

r r

r

r r rr

2x5+7x4+13x3+14x2+9x+10

r

r r r r

rr rr r

2x5+6x4+13x3+15x2+9x+10

r r rr

r rrr r r

x5+6x4+15x3+14x2+9x+10

rr r r

r rrr rr

x5+6x4+14x3+15x2+9x+10

r r r r

r rr r rr

x5+6x4+11x3+18x2+9x+10

r r

rr

r r

r

rr r

12x4+12x3+12x2+9x+10

r r

r r

r r r

rr r

12x4+7x3+17x2+9x+10

r

r

r r

r rr

rr r

11x4+12x3+13x2+9x+10

r

r r

r r r r

rr r

10x4+7x3+19x2+9x+10

Page 10: Hosoya polynomial of small trees

r rr

r r

r

r r

r

r

9x4+15x3+12x2+9x+10

r r r r

r rr rr

r

9x4+12x3+15x2+9x+10

r rr r

r r

r

r rr

9x4+12x3+15x2+9x+10

r

r rr

r r

r

rr r

8x4+15x3+13x2+9x+10

r r r

r r

rr

r rr

8x4+12x3+16x2+9x+10

r r r

r

r rr r

r

r

7x4+15x3+14x2+9x+10

r

r r

r r

r r

r rr

6x4+16x3+14x2+9x+10

r

r r r

r

r r

r r r

6x4+15x3+15x2+9x+10

r r r r r

r rr rr

6x4+7x3+23x2+9x+10

r r

r r

r rr r

r

r

5x4+16x3+15x2+9x+10

r

r

r

r r r r

r r r

5x4+12x3+19x2+9x+10

r r r rr

r rrr r

4x4+16x3+16x2+9x+10

r

r r

r

r r r

r r r

4x4+15x3+17x2+9x+10

r r

r rr r r

r rr

3x4+16x3+17x2+9x+10

r r r

r

r r

r

r rr

3x4+15x3+18x2+9x+10

r r

rr r r r

r rr

2x4+15x3+19x2+9x+10

r r r r r

r rr rr

x4+12x3+23x2+9x+10

rr r r

r r

r r

rr

16x3+20x2+9x+10

r r

r r

r r r r

r r

15x3+21x2+9x+10

r

r r

r r r r r

r r

12x3+24x2+9x+10

r r

r r r r r r

r r

7x3+29x2+9x+10

r r r r r r r

r rr

36x2+9x+10

235 trees with 11 vertices:

r rr rrr r rrr r

x10+2x9+3x8+4x7+5x6+6x5+7x4+8x3+9x2+10x+11

r

r rr rrr r rrr

2x9+3x8+4x7+5x6+6x5+7x4+8x3+10x2+10x+11

r

r rr r rr r rrr

x9+3x8+4x7+5x6+6x5+7x4+9x3+10x2+10x+11

Page 11: Hosoya polynomial of small trees

r

r rrr r rr rrr

x9+2x8+4x7+5x6+6x5+8x4+9x3+10x2+10x+11

r

r rrr r rr r rr

x9+2x8+3x7+5x6+7x5+8x4+9x3+10x2+10x+11

rr

r rr rrr r rr

4x8+4x7+5x6+6x5+7x4+8x3+11x2+10x+11

r r

r rr rrr r rr

3x8+4x7+5x6+6x5+7x4+8x3+12x2+10x+11

r

r r

rrr rrrr r

2x8+5x7+5x6+6x5+7x4+9x3+11x2+10x+11

r

r r

r

r r rr rrr

2x8+4x7+5x6+6x5+8x4+10x3+10x2+10x+11

r

r r

rr rrr rr r

2x8+4x7+5x6+6x5+7x4+10x3+11x2+10x+11

r

r r

rr r r rrr r

2x8+3x7+6x6+6x5+8x4+9x3+11x2+10x+11

r

r r

rr r rrrr r

2x8+3x7+5x6+6x5+9x4+9x3+11x2+10x+11

r

r r

rr rr r rr r

2x8+3x7+4x6+8x5+8x4+9x3+11x2+10x+11

r r

r rrr rr rr r

x8+4x7+6x6+6x5+7x4+10x3+11x2+10x+11

r r

r rr r rr rrr

x8+4x7+5x6+6x5+7x4+10x3+12x2+10x+11

r

r r

r

rr r rr r r

x8+3x7+5x6+7x5+9x4+10x3+10x2+10x+11

r r

r rr r rr rr r

x8+3x7+5x6+7x5+8x4+10x3+11x2+10x+11

r r

r rr r rrrr r

x8+3x7+5x6+6x5+8x4+11x3+11x2+10x+11

r r

r rrr r rrr r

x8+3x7+4x6+7x5+9x4+10x3+11x2+10x+11

r

r r

r

r rr rrr r

x8+2x7+5x6+8x5+9x4+10x3+10x2+10x+11

rr

r rr rr r rrr

x8+2x7+5x6+6x5+10x4+10x3+11x2+10x+11

r r

r rrr r rr rr

x8+2x7+5x6+6x5+9x4+10x3+12x2+10x+11

r r

r rrrr r rrr

x8+2x7+4x6+7x5+9x4+11x3+11x2+10x+11

r r

r rr rr rrr r

x8+2x7+3x6+8x5+9x4+10x3+12x2+10x+11

Page 12: Hosoya polynomial of small trees

r

r r

r r

r rrrr r

6x7+5x6+6x5+7x4+8x3+13x2+10x+11

r

r r

r

r

r

r rrr r

4x7+6x6+6x5+8x4+10x3+11x2+10x+11

r

r r

r

r

r rrr r r

4x7+6x6+6x5+7x4+10x3+12x2+10x+11

r r r

r rr rrr rr

4x7+5x6+6x5+7x4+8x3+15x2+10x+11

r

r r

rr

r rrr rr

4x7+4x6+7x5+9x4+9x3+12x2+10x+11

rr r

r rrrr r rr

3x7+7x6+6x5+7x4+9x3+13x2+10x+11

r r

r rr r rrr

r

r

3x7+5x6+6x5+9x4+11x3+11x2+10x+11

rr r

r rr rrrrr

3x7+5x6+6x5+7x4+11x3+13x2+10x+11

rr r

r rr rr rrr

3x7+4x6+8x5+8x4+9x3+13x2+10x+11

rr r

r rr r rrrr

3x7+4x6+6x5+10x4+9x3+13x2+10x+11

r

r r r

rrr rrr r

2x7+7x6+6x5+7x4+10x3+13x2+10x+11

r

r r

r

r r

r

r rr r

2x7+6x6+7x5+8x4+11x3+11x2+10x+11

r

r r r

rrr rr r r

2x7+6x6+7x5+7x4+11x3+12x2+10x+11

r r

r

rr

r

r r

r

r r

2x7+5x6+8x5+10x4+10x3+10x2+10x+11

r

r

r

r

r

r rr rr r

2x7+5x6+8x5+9x4+10x3+11x2+10x+11

rrr

r rrrr rrr

2x7+5x6+7x5+8x4+11x3+12x2+10x+11

r

r r r

rr rrr rr

2x7+5x6+6x5+10x4+10x3+12x2+10x+11

r

r

r r

r

r r rrrr

2x7+5x6+6x5+8x4+12x3+12x2+10x+11

r

r r r

rr rrrr r

2x7+5x6+6x5+7x4+12x3+13x2+10x+11

r

r

r

rr

r

r rrr r

2x7+4x6+8x5+10x4+10x3+11x2+10x+11

Page 13: Hosoya polynomial of small trees

r

r

r rr

r

r r rrr

2x7+4x6+7x5+10x4+11x3+11x2+10x+11

r

r r r

rr r rr r r

2x7+4x6+7x5+9x4+11x3+12x2+10x+11

r

r

r r

r

r r rrrr

2x7+4x6+6x5+10x4+12x3+11x2+10x+11

r

r

r r

rr rrrr r

2x7+4x6+6x5+9x4+12x3+12x2+10x+11

r

r r r

rr rr rr r

2x7+3x6+8x5+9x4+10x3+13x2+10x+11

r

r

r r

rr r rrr r

2x7+3x6+7x5+10x4+11x3+12x2+10x+11

r

r r r

rr r rrr r

2x7+3x6+6x5+11x4+10x3+13x2+10x+11

rr r

r rrr rr rr

x7+5x6+8x5+7x4+11x3+13x2+10x+11

r r r

r rr r rrrr

x7+5x6+6x5+7x4+11x3+15x2+10x+11

r r

r rrr r rr

r

r

x7+4x6+8x5+10x4+11x3+11x2+10x+11

r

r

r

rrr

r

r rr r

x7+4x6+8x5+10x4+11x3+11x2+10x+11

r

r

r rr

r

r rrr r

x7+4x6+7x5+10x4+12x3+11x2+10x+11

rr r

r rrrr rr r

x7+4x6+7x5+9x4+12x3+12x2+10x+11

rr r

r rrr r rrr

x7+4x6+6x5+10x4+11x3+13x2+10x+11

rr r

r rr r rrrr

x7+4x6+6x5+8x4+13x3+13x2+10x+11

r

r

r r

r

rrr rrr

x7+3x6+7x5+11x4+12x3+11x2+10x+11

r

r

r r

r

rr r rr r

x7+3x6+7x5+10x4+12x3+12x2+10x+11

r r r

r rrr r rr r

x7+3x6+6x5+11x4+11x3+13x2+10x+11

rr r

r rr r rrr r

x7+3x6+6x5+10x4+13x3+12x2+10x+11

r r r

r rr r rrr r

x7+3x6+6x5+9x4+13x3+13x2+10x+11

Page 14: Hosoya polynomial of small trees

rr r

r rrrr rrr

x7+2x6+6x5+10x4+13x3+13x2+10x+11

r r r

r rrr r rr r

x7+2x6+6x5+10x4+11x3+15x2+10x+11

rr r

r r

r

r rr rr

9x6+6x5+7x4+8x3+15x2+10x+11

r

r r

r r r

r rrr r

8x6+6x5+7x4+8x3+16x2+10x+11

r r

r r

r

r

r

rr rr

6x6+8x5+8x4+10x3+13x2+10x+11

r

r r

r

r r

r rr r r

6x6+8x5+7x4+10x3+14x2+10x+11

r r

r

r rrr r

r

r r

6x6+7x5+9x4+11x3+12x2+10x+11

r r

r r

rr

rrr rr

6x6+7x5+7x4+11x3+14x2+10x+11

r

r r

r

r r

r rr r r

6x6+5x5+11x4+9x3+14x2+10x+11

r r

r r

r

rrr r

r

r

5x6+8x5+11x4+10x3+11x2+10x+11

r r r r

r rr rrrr

5x6+6x5+7x4+8x3+19x2+10x+11

rr r r

r rrrr rr

4x6+9x5+7x4+9x3+16x2+10x+11

rr

r r

r

r

r r rr r

4x6+8x5+11x4+10x3+12x2+10x+11

r

r r

r

r

r

r

r rr r

4x6+8x5+10x4+12x3+11x2+10x+11

r

r r

r

r

r r

r

r r r

4x6+8x5+9x4+12x3+12x2+10x+11

r

r r

r

r

r

r

r rr r

4x6+8x5+8x4+12x3+13x2+10x+11

rr

r r

rr

rr r rr

4x6+8x5+8x4+12x3+13x2+10x+11

r

r r

rr r

rrr rr

4x6+8x5+7x4+12x3+14x2+10x+11

r

r r

r rr rrr

r

r

4x6+6x5+11x4+12x3+12x2+10x+11

r

r r

r

r

r

r

r rr r

4x6+6x5+11x4+12x3+12x2+10x+11

Page 15: Hosoya polynomial of small trees

r

r r

r

rr

rr rr r

4x6+6x5+10x4+12x3+13x2+10x+11

r r r

r rr r rrr

r

4x6+6x5+10x4+12x3+13x2+10x+11

rr r r

r rr rrrr

4x6+6x5+7x4+12x3+16x2+10x+11

rr r r

r rr r rrr

4x6+5x5+11x4+9x3+16x2+10x+11

r r rr

r rr r rr r

4x6+4x5+13x4+10x3+14x2+10x+11

r

r r r r

rrr rr r

3x6+10x5+7x4+10x3+15x2+10x+11

r

r

r r

r

rrr r

r

r

3x6+8x5+11x4+12x3+11x2+10x+11

r

r r

r

rr

r

r rrr

3x6+8x5+11x4+10x3+13x2+10x+11

r r

r

r rrr r

r

r r

3x6+8x5+10x4+12x3+12x2+10x+11

r rr r

r rr rr rr

3x6+8x5+8x4+12x3+14x2+10x+11

r

r r r r

rr rrrr

3x6+7x5+10x4+11x3+14x2+10x+11

r

r

r r

r

rr

r

r rr

3x6+6x5+12x4+12x3+12x2+10x+11

r r

r r

r r

r r rrr

3x6+6x5+10x4+14x3+12x2+10x+11

r r

r

r rr r rr

r

r

3x6+6x5+9x4+14x3+13x2+10x+11

r

r r r r

rr rrr r

3x6+6x5+7x4+14x3+15x2+10x+11

r r

r

r rr r r

r

r r

3x6+5x5+12x4+13x3+12x2+10x+11

r rr r

r rr rr rr

3x6+5x5+10x4+13x3+14x2+10x+11

r

r r r r

rr r rr r

3x6+4x5+13x4+10x3+15x2+10x+11

Page 16: Hosoya polynomial of small trees

r r

r

r rr r r

r

r r

2x6+9x5+11x4+11x3+12x2+10x+11

r

r r r r

rrr rr r

2x6+9x5+7x4+11x3+16x2+10x+11

r

r r

r

r

r

r rrr r

2x6+8x5+11x4+12x3+12x2+10x+11

r r

r r

r

r r

r

r rr

2x6+8x5+10x4+12x3+13x2+10x+11

r

r r r r

rr rr r r

2x6+8x5+9x4+12x3+14x2+10x+11

rr

r r

r

r

r

r rr r

2x6+7x5+12x4+13x3+11x2+10x+11

r

r r

r

r

r

r rrr r

2x6+7x5+11x4+13x3+12x2+10x+11

r r

r r

r

rr r

r

r r

2x6+7x5+10x4+13x3+13x2+10x+11

r

r rr r

rr rr rr

2x6+7x5+9x4+13x3+14x2+10x+11

r r

r

r r

rrr rr r

2x6+7x5+9x4+13x3+14x2+10x+11

r

r r

r

rr

r

r rr r

2x6+6x5+12x4+12x3+13x2+10x+11

rr

r r

r

r r

r

rr r

2x6+6x5+11x4+14x3+12x2+10x+11

r

r r r

r

r

r r r r r

2x6+6x5+10x4+14x3+13x2+10x+11

r r

r

r r

r

r r rrr

2x6+6x5+8x4+14x3+15x2+10x+11

r

r r r r

rr rrr r

2x6+6x5+7x4+14x3+16x2+10x+11

r r

r

r r

rr rrr r

2x6+5x5+11x4+13x3+14x2+10x+11

rr

r

r r

r

r r rrr

2x6+5x5+10x4+15x3+13x2+10x+11

r

r rr r

rr rr rr

2x6+5x5+9x4+15x3+14x2+10x+11

r r

r

r r

r

r r rr r

2x6+4x5+12x4+14x3+13x2+10x+11

r r

r

r r

rr rrr r

2x6+4x5+11x4+14x3+14x2+10x+11

Page 17: Hosoya polynomial of small trees

r

r r r r

rr r rr r

2x6+3x5+13x4+11x3+16x2+10x+11

r r r

r rrrr rr

r

x6+8x5+11x4+12x3+13x2+10x+11

r r

r

r rr r r

r

r r

x6+7x5+12x4+13x3+12x2+10x+11

r r

r r

r r

rrr rr

x6+6x5+12x4+14x3+12x2+10x+11

r r

r

r r

r

rr r rr

x6+6x5+12x4+14x3+12x2+10x+11

r r

r

r

r

r

r r rrr

x6+6x5+11x4+14x3+13x2+10x+11

r r

r

r rrrr r

r

r

x6+6x5+11x4+14x3+13x2+10x+11

r r rr

r rrr rr r

x6+6x5+11x4+12x3+15x2+10x+11

r r r r

r rrr rr r

x6+6x5+10x4+12x3+16x2+10x+11

r r r r

r rr r rrr

x6+6x5+7x4+12x3+19x2+10x+11

r r

r

r rr

r

r rr r

x6+5x5+11x4+15x3+13x2+10x+11

r rr r

r rrr r rr

x6+5x5+10x4+15x3+14x2+10x+11

rr r r

r rr r rrr

x6+5x5+8x4+15x3+16x2+10x+11

r r

r

r r

r

rrr rr

x6+4x5+11x4+14x3+15x2+10x+11

r rr r

r rrr r rr

x6+4x5+10x4+16x3+14x2+10x+11

r r r r

r rr r rr r

x6+4x5+9x4+16x3+15x2+10x+11

r r r r

r rr r rr r

x6+3x5+10x4+15x3+16x2+10x+11

r r r r

r rrrr rr

x6+2x5+11x4+12x3+19x2+10x+11

r r

r r

r r r

r rr r

12x5+7x4+8x3+18x2+10x+11

r

r r

r r r r

r rr r

10x5+7x4+8x3+20x2+10x+11

r r

r r

r rr r

r

rr

9x5+11x4+11x3+14x2+10x+11

Page 18: Hosoya polynomial of small trees

rr r

r r

r r

r rr r

9x5+9x4+11x3+16x2+10x+11

r

r r

r r

r

r rrr

r

8x5+12x4+12x3+13x2+10x+11

r

r r

r r

r

r

r

r r r

8x5+11x4+12x3+14x2+10x+11

r r r

r r

r

r r

r

rr

8x5+11x4+10x3+16x2+10x+11

rr

r r

r r r

rrr r

8x5+10x4+10x3+17x2+10x+11

r r r

r r

rr

rr rr

8x5+8x4+12x3+17x2+10x+11

r r

r r

r

r r

rr

r r

6x5+13x4+14x3+12x2+10x+11

r

r r

r r

r r

r r

r r

6x5+12x4+14x3+13x2+10x+11

r

r

r r

rr r

rr rr

6x5+12x4+14x3+13x2+10x+11

r

r r r

r

r

r r

r

r r

6x5+12x4+12x3+15x2+10x+11

r

r r

rr

r

r

r

r rr

6x5+11x4+14x3+14x2+10x+11

rr r

r r

r

r

r

r rr

6x5+11x4+14x3+14x2+10x+11

r

r r r

r

r r

rr r r

6x5+11x4+12x3+16x2+10x+11

r

r r r

r

rr

r rrr

6x5+10x4+14x3+15x2+10x+11

r

r r r

r

r r

rr r r

6x5+9x4+14x3+16x2+10x+11

r r r r r

r rr rrr

6x5+7x4+8x3+24x2+10x+11

r r

r r

r rr r

r

rr

5x5+13x4+13x3+14x2+10x+11

r r r r

r rr r rr

r

5x5+11x4+13x3+16x2+10x+11

rr r r r

r rr rrr

5x5+11x4+9x3+20x2+10x+11

rr r r r

r rr rrr

5x5+7x4+13x3+20x2+10x+11

r

r

r

r r

r

r r r r

r

4x5+14x4+14x3+13x2+10x+11

r r r

r

r rrr r r

r

4x5+13x4+14x3+14x2+10x+11

r rr r r

r rr rrr

4x5+13x4+10x3+18x2+10x+11

Page 19: Hosoya polynomial of small trees

r rr

r r

r

r r r

r

r

4x5+12x4+16x3+13x2+10x+11

r

r

r r

r

r

r r

r

r r

4x5+12x4+16x3+13x2+10x+11

r

r

r r

r

r

r

r

rr r

4x5+11x4+16x3+14x2+10x+11

r

r r r

r

r

r

r

r rr

4x5+11x4+16x3+14x2+10x+11

rr

r r

r rr rr

r

r

4x5+11x4+16x3+14x2+10x+11

r

r r r

r

r

r r

r

r r

4x5+11x4+14x3+16x2+10x+11

r rr

r r

rr

r r rr

4x5+10x4+16x3+15x2+10x+11

r r r

r

r rr r r

r

r

4x5+10x4+16x3+15x2+10x+11

r

r r

rr r r

rr rr

4x5+10x4+14x3+17x2+10x+11

r

r r

r

r r r

r r r r

4x5+10x4+14x3+17x2+10x+11

r rr r r

r rr rrr

4x5+7x4+16x3+18x2+10x+11

r r

r r

r rrr

r

rr

3x5+13x4+15x3+14x2+10x+11

r

r r r r r

rr rr r

3x5+13x4+11x3+18x2+10x+11

r

r r

r r

r r

r r

r r

3x5+12x4+17x3+13x2+10x+11

r r

rr

r rrr

r

rr

3x5+11x4+17x3+14x2+10x+11

r

rr r

r

r r

r rr r

3x5+11x4+15x3+16x2+10x+11

r

r r

r r

r r

r r rr

3x5+10x4+17x3+15x2+10x+11

r

r r r

r

r r

r r r r

3x5+9x4+17x3+16x2+10x+11

r r

r r

r rr r r

r

r

3x5+9x4+17x3+16x2+10x+11

r

r r r r r

rr rr r

3x5+7x4+17x3+18x2+10x+11

r r r

r r

r

r

r

r rr

2x5+11x4+16x3+16x2+10x+11

r

r r r r r

rr rr r

2x5+11x4+12x3+20x2+10x+11

r r r

r r

r

r r

r

r r

2x5+10x4+18x3+15x2+10x+11

r

r r r

r

rr

r r rr

2x5+10x4+16x3+17x2+10x+11

r r r

r r

r

r r

r

r r

2x5+9x4+18x3+16x2+10x+11

r r

rr r r r

r rr r

2x5+9x4+18x3+16x2+10x+11

r

r

r

rr r r

r r rr

2x5+8x4+18x3+17x2+10x+11

Page 20: Hosoya polynomial of small trees

r r r

r

r r

r

r r rr

2x5+8x4+16x3+19x2+10x+11

r

r r r r r

rr rr r

2x5+7x4+16x3+20x2+10x+11

r rr r r

r rrr rr

x5+7x4+19x3+18x2+10x+11

rr r r r

r rrr rr

x5+7x4+17x3+20x2+10x+11

r r r r r

r rr r rr

x5+7x4+13x3+24x2+10x+11

r r r

rr

r rrr r

r

16x4+14x3+15x2+10x+11

rr r r

r r

r r

r rr

16x4+8x3+21x2+10x+11

r

rr r

r r

rr

r rr

15x4+14x3+16x2+10x+11

r r

r r

r r r r

rr r

15x4+8x3+22x2+10x+11

r

r

r r

r r rr

rr r

14x4+14x3+17x2+10x+11

r r rr

r rr r

r r

r

13x4+18x3+14x2+10x+11

r r rr

r r

r

r r

r

r

12x4+18x3+15x2+10x+11

r

r r

rr

r r

r

rr r

12x4+18x3+15x2+10x+11

rr r

r r

r r r

rr r

12x4+14x3+19x2+10x+11

r

r r

r r r r r

rr r

12x4+8x3+25x2+10x+11

r r

rr

r r r

r rr

r

11x4+18x3+16x2+10x+11

r r r r r

r rr rr

r

11x4+14x3+20x2+10x+11

r r r

r r

r r r

r rr

10x4+20x3+15x2+10x+11

r r r r

r r

rr

r rr

10x4+14x3+21x2+10x+11

r r

r

r

r r

r

r r

r

r

9x4+20x3+16x2+10x+11

r

r r r r

r rr rr

r

9x4+18x3+18x2+10x+11

r r rr r

r r

r

rr r

9x4+18x3+18x2+10x+11

r

r r rr

r r

r

rr r

8x4+20x3+17x2+10x+11

r

r r r

r

r r r

r r r

8x4+18x3+19x2+10x+11

r r r

r r

r rr r

r

r

7x4+20x3+18x2+10x+11

Page 21: Hosoya polynomial of small trees

r r r r r r

r rr rr

7x4+8x3+30x2+10x+11

r

r r

r rr r r

r rr

6x4+20x3+19x2+10x+11

r r

r r

r r

r r

r rr

6x4+20x3+19x2+10x+11

r

r

r

r r r r r

r r r

6x4+14x3+25x2+10x+11

r r

r r r

r rr r

r

r

5x4+20x3+20x2+10x+11

r

r r

r

r r r r

r r r

5x4+18x3+22x2+10x+11

r r r r rr

r rrr r

4x4+20x3+21x2+10x+11

r

r r r

r

r r r

r r r

4x4+20x3+21x2+10x+11

r r

r rr r r r

r rr

3x4+20x3+22x2+10x+11

r r r r

r

r r

r

r rr

3x4+18x3+24x2+10x+11

r r

rr r r r r

r rr

2x4+18x3+25x2+10x+11

r r r r r r

r rr rr

x4+14x3+30x2+10x+11

r r r

r r

r r r r

r r

20x3+25x2+10x+11

r r

r r

r r r r r

r r

18x3+27x2+10x+11

r

r r

r r r r r r

r r

14x3+31x2+10x+11

r r

r r r r r r r

r r

8x3+37x2+10x+11

r r r r r r r r

r rr

45x2+10x+11

Page 22: Hosoya polynomial of small trees

References

[1] H. Hosoya, On some counting polynomials in chemistry, Discrete Appl. Math. 19 (1988), 239–

257.

[2] I. Gutman, Some properties of the Wiener polynomial , Graph Theory Notes New York 25

(1993), 13–18.

[3] A. A. Dobrynin, Construction of graphs with a palindromic Wiener polynomial , Vychisl. Sistemy

151 (1994), 37–54.

[4] A. A. Dobrynin, Graphs with palindromic Wiener polynomials , Graph Theory Notes New York

27 (1994), 50–54.

[5] M. Lepovic, I. Gutman, A collective property of trees and chemical trees , J. Chem. Inf. Comput.

Sci. 38 (1998), 823–826.

[6] I. Gutman, E. Estrada, O. Ivanciuc, Some properties of the Wiener polynomial of trees , Graph

Theory Notes New York 36 (1999), in press.

[7] I. Gutman, Hosoya polynomial and the distance of the total graph of a tree, Publ. Elektrotehn.

Fak. (Beograd) Ser. Mat., in press.

[8] D. Stevanovic, The Hosoya polynomial of composite graphs , Discrete Math., in press.

[9] G. Caporossi, A. A. Dobrynin, I. Gutman, P. Hansen, Trees with palindromic Hosoya polyno-

mials , Graph Theory Notes New York, submitted.

[10] E. Estrada, O. Ivanciuc, I. Gutman, A. Gutierrez, L. Rodriguez, Extended Wiener indices. A

new set of descriptors for quantitative structure-property studies , New J. Chem. 22 (1998),

819–822.

Page 23: Hosoya polynomial of small trees

HOSOJINI POLINOMI STABALA SA DO 11 CVOROVA

Dragan Stevanovica i Ivan Gutmanb

aFilozofski fakultet, Cirila i Metodija 2, 18000 Nis, i

bPrirodno–matematicki fakultet, p.f. 60, 34000 Kragujevac

I Z V O D

Neka je G povezani graf. Ako je d(G, k) broj parova cvorova grafa G cije rastojanje je k , onda

se∑

k≥0d(G, k)xk naziva Hosojin polinom grafa G . Tabelirani su Hosojini polinomi svih stabala

sa 11 ili manje cvorova (1 + 1 + 1 + 2 + 3 + 6 + 11 + 23 + 47 + 106 + 235 stabala).