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 A376381 #15 Sep 22 2024 11:05:52
%S A376381 1,0,4,6,272,1570,63912,792554,33262784,684763650,30981768680,
%T A376381 915838324522,45524048263872,1765020653500130,97096528136899592,
%U A376381 4651295721203951850,283478019364268181632,16107548441248677913858,1084981357752210351649512,71056829948555342150405354,5267564532376249471978526720
%N A376381 Expansion of e.g.f. (1/x) * Series_Reversion( x*(1 - x*(exp(x) - 1))^2 ).
%H A376381 <a href="/index/Res#revert">Index entries for reversions of series</a>
%F A376381 E.g.f. A(x) satisfies A(x) = 1/(1 - x*A(x) * (exp(x*A(x)) - 1))^2.
%F A376381 E.g.f.: B(x)^2, where B(x) is the e.g.f. of A371271.
%F A376381 a(n) = (2 * n!/(2*n+2)!) * Sum_{k=0..floor(n/2)} (2*n+k+1)! * Stirling2(n-k,k)/(n-k)!.
%o A376381 (PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(serreverse(x*(1-x*(exp(x)-1))^2)/x))
%o A376381 (PARI) a(n) = 2*n!*sum(k=0, n\2, (2*n+k+1)!*stirling(n-k, k, 2)/(n-k)!)/(2*n+2)!;
%Y A376381 Cf. A371271, A375660.
%K A376381 nonn
%O A376381 0,3
%A A376381 _Seiichi Manyama_, Sep 22 2024