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 A380663 #9 Jan 30 2025 03:50:00
%S A380663 1,2,15,208,4285,117936,4075099,169736960,8282604537,463604723200,
%T A380663 29287449579751,2061571190059008,160023548976361525,
%U A380663 13580237335641417728,1250935473495646861875,124307671411309327876096,13255531892787507819759601,1509841440567809574906101760
%N A380663 Expansion of e.g.f. (1/x) * Series_Reversion( x * (1 - x) * exp(-x/(1 - x)) ).
%H A380663 <a href="/index/Res#revert">Index entries for reversions of series</a>
%F A380663 E.g.f. A(x) satisfies A(x) = exp(x * A(x)/(1 - x*A(x)))/(1 - x*A(x)).
%F A380663 a(n) = n! * Sum_{k=0..n} (n+1)^(k-1) * binomial(2*n,n-k)/k!.
%o A380663 (PARI) a(n) = n!*sum(k=0, n, (n+1)^(k-1)*binomial(2*n, n-k)/k!);
%Y A380663 Cf. A377831, A380664.
%Y A380663 Cf. A052873, A380665.
%K A380663 nonn
%O A380663 0,2
%A A380663 _Seiichi Manyama_, Jan 30 2025