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 A006718 Number of golygons of length 8n. (Formerly M3707) 3
 1, 4, 112, 8432, 909288, 121106960, 18167084064, 2956370702688, 510696155882492, 92343039606440064, 17311893232788414400, 3342127071364266721200, 661066887819006986788620, 133456726466163517072371360 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS A007219 is the main entry for golygons. REFERENCES N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). I. Vardi, Computational Recreations in Mathematica. Addison-Wesley, Redwood City, CA, 1991, p. 92. LINKS Seiichi Manyama, Table of n, a(n) for n = 0..200 Eric Weisstein's World of Mathematics, Golygon FORMULA a(n) = 4 * A007219(n) for n > 0. - Charles R Greathouse IV, Apr 29 2012 a(n) = A060468(n) * A292476(2*n) = A063865(4*n) * A292476(2*n). - Seiichi Manyama, Sep 18 2017 MATHEMATICA p1[n_] := Product[x^k + 1, {k, 1, n - 1, 2}] // Expand; p2[n_] := Product[x^k + 1, {k, 1, n/2}] // Expand; c[n_] := Coefficient[p1[n], x, n^2/8] * Coefficient[p2[n], x, n (n/2 + 1)/8]; a[n_] := c[8*n]; Table[a[n], {n, 0, 11}] (* Jean-François Alcover, Jul 24 2013, after Eric W. Weisstein *) CROSSREFS Cf. A060468, A063865, A292476. See A007219 for much more information about golygons. Sequence in context: A063406 A221625 A013151 * A185320 A293158 A196458 Adjacent sequences:  A006715 A006716 A006717 * A006719 A006720 A006721 KEYWORD nonn AUTHOR EXTENSIONS a(0) = 1 prepended by Seiichi Manyama, Sep 18 2017 STATUS approved

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Last modified January 16 03:36 EST 2021. Contains 340195 sequences. (Running on oeis4.)