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 A107965 a(n) = (n+1)(n+2)^2*(n+3)^2*(n+4)(11n^4 + 110n^3 + 439n^2 + 820n + 600)/86400. 2
 1, 33, 421, 3171, 16954, 71148, 249228, 758934, 2066559, 5135845, 11828817, 25546885, 52216164, 101751664, 190171248, 342572508, 597234429, 1011161361, 1667449861, 2684929863, 4230610846, 6535551660, 9914869900, 14792713650, 21733135515, 31477936581 (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 T. D. Noe, Table of n, a(n) for n = 0..1000 Index entries for linear recurrences with constant coefficients, signature (11,-55,165,-330,462,-462,330,-165,55,-11,1). FORMULA G.f.: -(x^6+22*x^5+113*x^4+190*x^3+113*x^2+22*x+1) / (x-1)^11. - Colin Barker, Aug 13 2013 MAPLE a:=n->(1/86400)*(n+1)*(n+2)^2*(n+3)^2*(n+4)*(11*n^4+110*n^3+439*n^2+820*n+600): seq(a(n), n=0..26); CROSSREFS Sequence in context: A202256 A324950 A252925 * A220591 A296839 A296988 Adjacent sequences:  A107962 A107963 A107964 * A107966 A107967 A107968 KEYWORD nonn,easy AUTHOR Emeric Deutsch, Jun 12 2005 STATUS approved

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Last modified December 2 05:01 EST 2021. Contains 349437 sequences. (Running on oeis4.)