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 A368265 #12 Dec 29 2023 06:27:08
%S A368265 1,3,12,65,460,4057,42922,529769,7472808,118586033,2090936014,
%T A368265 40554647377,858082563532,19668880007129,485528656965762,
%U A368265 12841428220413593,362276791422785488,10859170086870710497,344648459867067117334,11546148650974694099201
%N A368265 Expansion of e.g.f. exp(2*x) / (1 - x*exp(x)).
%F A368265 a(n) = n! * Sum_{k=0..n} (n-k+2)^k / k!.
%F A368265 a(n) ~ n! / ((1 + LambertW(1)) * LambertW(1)^(n+2)). - _Vaclav Kotesovec_, Dec 29 2023
%o A368265 (PARI) a(n) = n!*sum(k=0, n, (n-k+2)^k/k!);
%Y A368265 Cf. A006153, A072597, A092148, A368266.
%Y A368265 Cf. A368267, A368271.
%K A368265 nonn,easy
%O A368265 0,2
%A A368265 _Seiichi Manyama_, Dec 19 2023