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 A377861 #9 Nov 10 2024 05:01:10
%S A377861 1,2,15,206,4193,113904,3882511,159475280,7672503681,423360926720,
%T A377861 26362968645071,1829066086810368,139929538526047585,
%U A377861 11703312997355442176,1062423600515479191375,104042389901715413633024,10933256593926589800851969,1227201235266954603172331520
%N A377861 Expansion of e.g.f. (1/x) * Series_Reversion( x * (1 - x)^3 * exp(x) ).
%H A377861 <a href="/index/Res#revert">Index entries for reversions of series</a>
%F A377861 E.g.f. A(x) satisfies A(x) = exp(-x * A(x))/(1 - x*A(x))^3.
%F A377861 a(n) = n! * Sum_{k=0..n} (-1)^k * (n+1)^(k-1) * binomial(4*n-k+2,n-k)/k!.
%o A377861 (PARI) a(n) = n!*sum(k=0, n, (-1)^k*(n+1)^(k-1)*binomial(4*n-k+2, n-k)/k!);
%Y A377861 Cf. A377859, A377860.
%Y A377861 Cf. A377833.
%K A377861 nonn
%O A377861 0,2
%A A377861 _Seiichi Manyama_, Nov 09 2024