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 A380664 #9 Jan 30 2025 03:50:54
%S A380664 1,2,17,268,6277,196416,7716109,365398496,20271580137,1290027358720,
%T A380664 92653747607401,7414981595716608,654373744057368493,
%U A380664 63136350047908917248,6612064512998173129125,747016321343021395603456,90564758322246657646854481,11727981253987656671672008704
%N A380664 Expansion of e.g.f. (1/x) * Series_Reversion( x * (1 - x) * exp(-x/(1 - x)^2) ).
%H A380664 <a href="/index/Res#revert">Index entries for reversions of series</a>
%F A380664 E.g.f. A(x) satisfies A(x) = exp(x * A(x)/(1 - x*A(x))^2)/(1 - x*A(x)).
%F A380664 a(n) = n! * Sum_{k=0..n} (n+1)^(k-1) * binomial(2*n+k,n-k)/k!.
%o A380664 (PARI) a(n) = n!*sum(k=0, n, (n+1)^(k-1)*binomial(2*n+k, n-k)/k!);
%Y A380664 Cf. A377831, A380663.
%Y A380664 Cf. A361598.
%K A380664 nonn
%O A380664 0,2
%A A380664 _Seiichi Manyama_, Jan 30 2025