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A108645 (n+1)(n+2)^2*(n+3)^2*(n+4)(2n^2+6n+5)/720. 0
1, 26, 250, 1435, 5978, 19992, 56952, 143550, 328515, 695266, 1379378, 2591953, 4650100, 8015840, 13344864, 21546684, 33857829, 51929850, 77934010, 114684647, 165783310, 235785880, 330395000, 456680250, 623328615, 840927906, 1122285906 (list; graph; refs; listen; history; 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.230, no. 21).

MAPLE

a:=(n+1)*(n+2)^2*(n+3)^2*(n+4)*(2*n^2+6*n+5)/720: seq(a(n), n=0..30);

CROSSREFS

Sequence in context: A184461 A088889 A060105 * A086023 A125389 A109467

Adjacent sequences:  A108642 A108643 A108644 * A108646 A108647 A108648

KEYWORD

nonn

AUTHOR

Emeric Deutsch (deutsch(AT)duke.poly.edu), Jun 13 2005

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Last modified February 16 01:31 EST 2012. Contains 205860 sequences.