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 A381304 #7 Feb 20 2025 08:39:38
%S A381304 1,1,2,7,36,241,1984,19461,222080,2892361,42350976,688911763,
%T A381304 12329035264,240789209025,5096898326528,116247332597833,
%U A381304 2842225449025536,74165478671163601,2057366115038003200,60461340544432547391,1876511245926278365184,61336532673286072390321
%N A381304 E.g.f. A(x) satisfies A(x) = 1/( 1 - sinh(x * A(x)^(1/2)) / A(x)^(1/2) ).
%F A381304 a(n) = Sum_{k=0..n} k! * binomial(n/2+k/2+1,k)/(n/2+k/2+1) * A136630(n,k).
%o A381304 (PARI) a136630(n, k) = 1/(2^k*k!)*sum(j=0, k, (-1)^(k-j)*(2*j-k)^n*binomial(k, j));
%o A381304 a(n) = sum(k=0, n, k!*binomial(n/2+k/2+1, k)/(n/2+k/2+1)*a136630(n, k));
%Y A381304 Cf. A136630.
%K A381304 nonn
%O A381304 0,3
%A A381304 _Seiichi Manyama_, Feb 19 2025