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A107959 a(n) = (n+1)(n+2)^2*(n+3)^2*(n+4)(n^2 + 5n + 5)/720. 0
1, 22, 190, 1015, 4018, 12936, 35784, 88110, 197835, 412126, 806806, 1498861, 2662660, 4550560, 7518624, 12058236, 18834453, 28731990, 42909790, 62865187, 90508726, 128250760, 179101000, 246782250, 335859615, 451886526, 601568982 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Kekulé numbers for certain benzenoids.

REFERENCES

S. J. Cyvin and I. Gutman, Kekulé 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->(1/720)*(n+1)*(n+2)^2*(n+3)^2*(n+4)*(n^2+5*n+5): seq(a(n), n=0..30);

CROSSREFS

Sequence in context: A231749 A072040 A022682 * A200936 A110690 A020923

Adjacent sequences:  A107956 A107957 A107958 * A107960 A107961 A107962

KEYWORD

nonn

AUTHOR

Emeric Deutsch, Jun 12 2005

STATUS

approved

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Last modified December 10 23:18 EST 2019. Contains 329910 sequences. (Running on oeis4.)