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 A331611 #7 Jan 26 2020 18:07:08
%S A331611 1,1,10,241,10585,732826,73233205,9955632961,1764233731270,
%T A331611 394629336427021,108652463882802505,36084903957564392206,
%U A331611 14217903951354603567385,6554505383225768210009041,3493988190176442653240091010,2131975894217009666242489287001
%N A331611 E.g.f.: exp(1 / (2 - cosh(x)) - 1) (even powers only).
%F A331611 a(0) = 1; a(n) = Sum_{k=1..n} binomial(2*n-1,2*k-1) * A094088(k) * a(n-k).
%F A331611 a(n) ~ 2^(2*n + 1/4) * exp(1/(2*sqrt(3)*log(2 + sqrt(3))) - 2/3 + sqrt(8*n/log(2 + sqrt(3)))/3^(1/4) - 2*n) * n^(2*n - 1/4) / (3^(1/8) * log(2 + sqrt(3))^(2*n + 1/4)). - _Vaclav Kotesovec_, Jan 26 2020
%t A331611 nmax = 15; Table[(CoefficientList[Series[Exp[1/(2 - Cosh[x]) - 1], {x, 0, 2 nmax}], x] Range[0, 2 nmax]!)[[n]], {n, 1, 2 nmax + 1, 2}]
%t A331611 A094088[0] = 1; A094088[n_] := A094088[n] = Sum[Binomial[2 n, 2 k] A094088[n - k], {k, 1, n}]; a[0] = 1; a[n_] := a[n] = Sum[Binomial[2 n - 1, 2 k - 1] A094088[k] a[n - k], {k, 1, n}]; Table[a[n], {n, 0, 15}]
%Y A331611 Cf. A005046, A050351, A075729, A094088, A331608, A331612.
%K A331611 nonn
%O A331611 0,3
%A A331611 _Ilya Gutkovskiy_, Jan 22 2020