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A107962
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(1/720)(n+1)(n+2)^2*(n+3)(n+4)(5n^2+18n+15).
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1
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1, 19, 142, 665, 2338, 6762, 16968, 38214, 79035, 152581, 278278, 483847, 807716, 1301860, 2035104, 3096924, 4601781, 6694023, 9553390, 13401157, 18506950, 25196270, 33858760, 44957250, 59037615, 76739481, 98807814, 126105427
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| Kekule numbers for certain benzenoids.
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REFERENCES
| S. J. Cyvin and I. Gutman, Kekule structures in benzenoid hydrocarbons, Lecture Notes in Chemistry, No. 46, Springer, New York, 1988 (p. 229).
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FORMULA
| O.g.f.: (1+11*x+18*x^2+5*x^3)/(-1+x)^8. - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Apr 07 2008
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MAPLE
| a:=n->(1/720)*(n+1)*(n+2)^2*(n+3)*(n+4)*(5*n^2+18*n+15): seq(a(n), n=0..30);
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CROSSREFS
| Sequence in context: A060104 A201151 A110694 * A002615 A081590 A093646
Adjacent sequences: A107959 A107960 A107961 * A107963 A107964 A107965
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KEYWORD
| nonn
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AUTHOR
| Emeric Deutsch (deutsch(AT)duke.poly.edu), Jun 12 2005
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