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 A380828 #12 Feb 05 2025 09:23:40
%S A380828 1,3,26,398,8904,264072,9790192,436382256,22748241024,1358633214080,
%T A380828 91503397265664,6862436244211968,567252637423922176,
%U A380828 51244493078278198272,5023312927780022323200,531082672018567209801728,60239691905397303186849792,7297357396264290237329473536
%N A380828 Expansion of e.g.f. (1/x) * Series_Reversion( x * exp(-2*x) / (1 + x) ).
%H A380828 <a href="/index/Res#revert">Index entries for reversions of series</a>
%F A380828 E.g.f. A(x) satisfies A(x) = exp(2*x*A(x)) / ( 1 - x*exp(2*x*A(x)) ).
%F A380828 a(n) = n! * Sum_{k=0..n} (2*n+2)^k * binomial(n,k)/(k+1)!.
%F A380828 a(n) = A376093(n+1)/(n+1).
%o A380828 (PARI) a(n) = n!*sum(k=0, n, (2*n+2)^k*binomial(n, k)/(k+1)!);
%Y A380828 Cf. A352448, A380808.
%Y A380828 Cf. A088690, A380830.
%Y A380828 Cf. A376093.
%K A380828 nonn
%O A380828 0,2
%A A380828 _Seiichi Manyama_, Feb 05 2025