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 A381442 #9 Feb 24 2025 04:23:46
%S A381442 1,2,10,86,1080,18042,377936,9538622,281946496,9557102450,
%T A381442 365548361472,15576454300134,731807446707200,37584596599753322,
%U A381442 2094995668172597248,125966553940498047182,8127048592610380578816,560040497770823162810082,41054563701320694564061184
%N A381442 Expansion of e.g.f. (1/x) * Series_Reversion( x/(1 + sinh(x))^2 ).
%H A381442 <a href="/index/Res#revert">Index entries for reversions of series</a>
%F A381442 E.g.f. A(x) satisfies A(x) = (1 + sinh(x*A(x)))^2.
%F A381442 E.g.f.: B(x)^2, where B(x) is the e.g.f. of A198865.
%F A381442 a(n) = (1/(n+1)) * Sum_{k=0..n} k! * binomial(2*n+2,k) * A136630(n,k).
%o A381442 (PARI) a136630(n, k) = 1/(2^k*k!)*sum(j=0, k, (-1)^(k-j)*(2*j-k)^n*binomial(k, j));
%o A381442 a(n) = sum(k=0, n, k!*binomial(2*n+2, k)*a136630(n, k))/(n+1);
%Y A381442 Cf. A136630, A198865.
%K A381442 nonn
%O A381442 0,2
%A A381442 _Seiichi Manyama_, Feb 23 2025