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 A346371 #5 Jul 14 2021 14:55:31
%S A346371 1,1,2,10,88,1496,34256,1305872,57804160,3960382848,288097804032,
%T A346371 31177032137472,3374496463248384,530644850402565120,
%U A346371 79955455534325999616,17241179374803330287616,3448609425518084068048896,977269122457749276877750272,250420488297020919542581493760
%N A346371 Sum_{n>=0} a(n) * x^n / (n!)^2 = exp( Sum_{n>=0} x^(2*n+1) / (2*n+1)^2 ).
%F A346371 a(0) = 1; a(n) = (1/n) * Sum_{k=0..floor((n-1)/2)} (binomial(n,2*k+1) * (2*k+1)!)^2 * a(n-2*k-1) / (2*k+1).
%t A346371 nmax = 18; CoefficientList[Series[Exp[Sum[x^(2 k + 1)/(2 k + 1)^2, {k, 0, Infinity}]], {x, 0, nmax}], x] Range[0, nmax]!^2
%t A346371 a[0] = 1; a[n_] := a[n] = (1/n) Sum[(Binomial[n, 2 k + 1] (2 k + 1)!)^2 a[n - 2 k - 1]/(2 k + 1), {k, 0, Floor[(n - 1)/2]}]; Table[a[n], {n, 0, 18}]
%Y A346371 Cf. A000246, A074707.
%K A346371 nonn
%O A346371 0,3
%A A346371 _Ilya Gutkovskiy_, Jul 14 2021