This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A375664 #10 Sep 01 2024 09:35:15
%S A375664 1,0,0,12,0,120,2160,1680,120960,1481760,6350400,240166080,2754259200,
%T A375664 31152401280,894303970560,11769588230400,228232766361600,
%U A375664 5845147711603200,98290727395660800,2502848611354291200,63417766359467520000,1376904298716724377600
%N A375664 Expansion of e.g.f. 1 / (1 - x * (exp(x^2) - 1))^2.
%F A375664 E.g.f.: B(x)^2, where B(x) is the e.g.f. of A375588.
%F A375664 a(n) = n! * Sum_{k=0..floor(n/2)} (n-2*k+1)! * Stirling2(k,n-2*k)/k!.
%o A375664 (PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(1/(1+x-x*exp(x^2))^2))
%o A375664 (PARI) a(n) = n!*sum(k=0, n\2, (n-2*k+1)!*stirling(k, n-2*k, 2)/k!);
%Y A375664 Cf. A375588, A375665.
%K A375664 nonn
%O A375664 0,4
%A A375664 _Seiichi Manyama_, Aug 23 2024