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 A370700 #7 Feb 27 2024 09:48:18
%S A370700 1,1,0,0,12,60,240,1680,15120,136080,1330560,14636160,176299200,
%T A370700 2291889600,32069157120,481037356800,7697116627200,130850982662400,
%U A370700 2355300044697600,44750700849254400,895014687427660800,18795308435980876800,413496757432991232000
%N A370700 Expansion of e.g.f. exp(-x^2)/(1-x).
%F A370700 a(n) = n! * Sum_{k=0..floor(n/2)} (-1)^k/k!.
%o A370700 (PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(exp(-x^2)/(1-x)))
%o A370700 (PARI) a(n) = n!*sum(k=0, n\2, (-1)^k/k!);
%Y A370700 Cf. A000166, A370701.
%Y A370700 Cf. A355268.
%K A370700 nonn,easy
%O A370700 0,5
%A A370700 _Seiichi Manyama_, Feb 27 2024