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 A376444 #12 Sep 23 2024 09:28:43
%S A376444 1,0,0,18,0,180,23760,2520,1693440,180033840,107956800,42093263520,
%T A376444 4131388800000,7363478041920,2262271571239680,213613512570057600,
%U A376444 843365230060953600,226557537882970694400,20988751571439158707200,154613821575430253836800,38125864157166326661120000,3508865828606684108929766400
%N A376444 Expansion of e.g.f. (1/x) * Series_Reversion( x*(1 - x*(exp(x^2) - 1))^3 ).
%H A376444 <a href="/index/Res#revert">Index entries for reversions of series</a>
%F A376444 E.g.f. A(x) satisfies A(x) = 1/(1 - x*A(x) * (exp(x^2*A(x)^2) - 1))^3.
%F A376444 a(n) = (3 * n!/(3n+3)!) * Sum_{k=0..floor(n/2)} (4*n-2*k+2)! * Stirling2(k,n-2*k)/k!.
%o A376444 (PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(serreverse(x*(1-x*(exp(x^2)-1))^3)/x))
%o A376444 (PARI) a(n) = 3*n!*sum(k=0, n\2, (4*n-2*k+2)!*stirling(k, n-2*k, 2)/k!)/(3*n+3)!;
%Y A376444 Cf. A376345, A376443.
%Y A376444 Cf. A375665.
%K A376444 nonn
%O A376444 0,4
%A A376444 _Seiichi Manyama_, Sep 22 2024