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 A379936 #11 Jan 07 2025 07:20:21
%S A379936 1,4,30,344,5400,108492,2667952,77811120,2629399680,101122817300,
%T A379936 4363964377344,208925612290056,10992411683169280,630611992509716700,
%U A379936 39182624685283891200,2621745777377998537568,187969244952968687812608,14377545994804829244970020
%N A379936 E.g.f. A(x) satisfies A(x) = 1/( exp(-x*A(x)^(1/2)) - x )^2.
%F A379936 E.g.f.: ( (1/x) * Series_Reversion( x*exp(-x)/(1+x) ) )^2.
%F A379936 E.g.f.: B(x)^2, where B(x) is the e.g.f. of A088690.
%F A379936 a(n) = 2 * n! * Sum_{k=0..n} (n+2)^(k-1) * binomial(n+2,n-k)/k!.
%o A379936 (PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace((serreverse(x*exp(-x)/(1+x))/x)^2))
%o A379936 (PARI) a(n) = 2*n!*sum(k=0, n, (n+2)^(k-1)*binomial(n+2, n-k)/k!);
%Y A379936 Cf. A379933, A379934.
%Y A379936 Cf. A088690.
%K A379936 nonn
%O A379936 0,2
%A A379936 _Seiichi Manyama_, Jan 06 2025