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 A377534 #8 Oct 31 2024 13:18:33
%S A377534 1,3,12,78,648,6300,72000,939960,13749120,223035120,3969907200,
%T A377534 76890733920,1609732776960,36214043785920,871131980759040,
%U A377534 22310233170825600,606026217929932800,17401756135956192000,526641334386809241600,16753142420507766873600
%N A377534 Expansion of e.g.f. 1/(1 - x * exp(x^2))^3.
%F A377534 a(n) = n! * Sum_{k=0..floor(n/2)} (n-2*k)^k * binomial(n-2*k+2,2)/k!.
%F A377534 a(n) ~ n! * n^2 * 2^(n/2 - 1) / ((1 + LambertW(2))^3 * LambertW(2)^(n/2)). - _Vaclav Kotesovec_, Oct 31 2024
%o A377534 (PARI) a(n) = n!*sum(k=0, n\2, (n-2*k)^k*binomial(n-2*k+2, 2)/k!);
%Y A377534 Cf. A358064, A377533.
%K A377534 nonn,easy
%O A377534 0,2
%A A377534 _Seiichi Manyama_, Oct 31 2024