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 A109116 a(n) = (n+1)^3*(n+2)^2*(n+5). 1
 20, 432, 3024, 12800, 40500, 105840, 241472, 497664, 947700, 1694000, 2874960, 4672512, 7320404, 11113200, 16416000, 23674880, 33428052, 46317744, 63102800, 84672000, 112058100, 146452592, 189221184, 241920000, 306312500, 384387120 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS KekulĂ© numbers for certain benzenoids. REFERENCES S. J. Cyvin and I. Gutman, KekulĂ© structures in benzenoid hydrocarbons, Lecture Notes in Chemistry, No. 46, Springer, New York, 1988 (p. 310). LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..10000 FORMULA G.f.: 4(5 + 73z + 105z^2 + z^3 - 4z^4)/(1-z)^7. MAPLE a:=n->(n+1)^3*(n+2)^2*(n+5): seq(a(n), n=0..30); MATHEMATICA Table[(n+1)^3 (n+2)^2 (n+5), {n, 0, 30}] (* Harvey P. Dale, Sep 24 2011 *) PROG (MAGMA) [(n+1)^3*(n+2)^2*(n+5): n in [0..30]]; // Vincenzo Librandi, Sep 25 2011 CROSSREFS Sequence in context: A215290 A130832 A180810 * A190922 A136257 A320765 Adjacent sequences:  A109113 A109114 A109115 * A109117 A109118 A109119 KEYWORD nonn,easy AUTHOR Emeric Deutsch, Jun 19 2005 STATUS approved

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Last modified June 1 20:49 EDT 2020. Contains 334765 sequences. (Running on oeis4.)