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%I M3707 #41 May 11 2018 04:27:43
%S 1,4,112,8432,909288,121106960,18167084064,2956370702688,
%T 510696155882492,92343039606440064,17311893232788414400,
%U 3342127071364266721200,661066887819006986788620,133456726466163517072371360
%N Number of golygons of length 8n.
%C A007219 is the main entry for golygons.
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%D I. Vardi, Computational Recreations in Mathematica. Addison-Wesley, Redwood City, CA, 1991, p. 92.
%H Seiichi Manyama, <a href="/A006718/b006718.txt">Table of n, a(n) for n = 0..200</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Golygon.html">Golygon</a>
%F a(n) = 4 * A007219(n) for n > 0. - _Charles R Greathouse IV_, Apr 29 2012
%F a(n) = A060468(n) * A292476(2*n) = A063865(4*n) * A292476(2*n). - _Seiichi Manyama_, Sep 18 2017
%t 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_ *)
%Y Cf. A060468, A063865, A292476.
%Y See A007219 for much more information about golygons.
%K nonn
%O 0,2
%A _N. J. A. Sloane_
%E a(0) = 1 prepended by _Seiichi Manyama_, Sep 18 2017
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