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 A366459 #17 Dec 29 2023 06:20:08
%S A366459 0,0,2,6,24,140,990,8442,84056,955656,12227130,173812430,2717859012,
%T A366459 46362339036,856770362630,17050946225250,363576478312560,
%U A366459 8269357341437072,199837364514425586,5113346326011170838,138106722548779770620,3926456810081828991780
%N A366459 Expansion of e.g.f. -log(1 - x^2 * exp(x)).
%F A366459 a(n) = n! * Sum_{k=1..floor(n/2)} k^(n-2*k-1)/(n-2*k)!.
%F A366459 a(n) ~ (n-1)! / (2^n *LambertW(1/2)^n). - _Vaclav Kotesovec_, Dec 29 2023
%o A366459 (PARI) a(n) = n!*sum(k=1, n\2, k^(n-2*k-1)/(n-2*k)!);
%Y A366459 Cf. A009444, A366546.
%Y A366459 Cf. A216507, A346753, A358080.
%K A366459 nonn
%O A366459 0,3
%A A366459 _Seiichi Manyama_, Dec 14 2023