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 A380762 #27 Feb 03 2025 11:08:03
%S A380762 1,2,15,208,4249,115656,3946879,162225680,7807264497,430828353280,
%T A380762 26825288214031,1860715287986688,142304071119852745,
%U A380762 11897080341213068288,1079508321205459768575,105660694801273960216576,11097101798773200862180321,1244852059489783737208012800
%N A380762 Expansion of e.g.f. (1/x) * Series_Reversion( x * exp(-x * (1 + x)^2) / (1 + x) ).
%H A380762 <a href="/index/Res#revert">Index entries for reversions of series</a>
%F A380762 E.g.f. A(x) satisfies A(x) = exp( x * A(x) * (1 + x*A(x))^2 ) * (1 + x*A(x)).
%F A380762 a(n) = n! * Sum_{k=0..n} (n+1)^(k-1) * binomial(n+2*k+1,n-k)/k!.
%o A380762 (PARI) a(n, q=1, r=1, s=1, t=2, u=1) = q*n!*sum(k=0, n, (r*n+(s-r)*k+q)^(k-1)*binomial(r*u*n+((s-r)*u+t)*k+q*u, n-k)/k!);
%Y A380762 Cf. A000129, A088690.
%Y A380762 Cf. A365031, A380781.
%Y A380762 Cf. A380664.
%K A380762 nonn
%O A380762 0,2
%A A380762 _Seiichi Manyama_, Feb 02 2025