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A107956 (1/2880)(n+1)(n+2)^2*(n+3)^2*(n+4)(5n^2+21n+20). 0
1, 23, 205, 1120, 4508, 14700, 41076, 101970, 230505, 482911, 949949, 1772134, 3159520, 5416880, 8975184, 14430348, 22590297, 34531455, 51665845, 75820052, 109327372, 155134540, 216924500, 299256750, 407726865, 549146871, 731748213 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Kekule numbers for certain benzenoids.

REFERENCES

S. J. Cyvin and I. Gutman, Kekule structures in benzenoid hydrocarbons, Lecture Notes in Chemistry, No. 46, Springer, New York, 1988 (p. 229).

LINKS

Table of n, a(n) for n=0..26.

MAPLE

a:=n->(1/2880)*(n+1)*(n+2)^2*(n+3)^2*(n+4)*(5*n^2+21*n+20): seq(a(n), n=0..30);

CROSSREFS

Sequence in context: A060882 A221670 A128334 * A022683 A042020 A084428

Adjacent sequences:  A107953 A107954 A107955 * A107957 A107958 A107959

KEYWORD

nonn

AUTHOR

Emeric Deutsch, Jun 12 2005

STATUS

approved

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Last modified May 19 10:28 EDT 2013. Contains 225429 sequences.