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 A353891 #11 May 10 2022 11:42:08
%S A353891 1,0,0,0,6,30,165,1050,8932,86184,909360,10393020,129313206,
%T A353891 1743627600,25314159780,393346535400,6512022804960,114430467296880,
%U A353891 2127154061337480,41703621476302800,859966710771029040,18606040434320713920,421427283751799685360
%N A353891 Expansion of e.g.f. exp( (x * log(1-x))^2 / 4 ).
%F A353891 a(n) = n! * Sum_{k=0..floor(n/4)} (2*k)! * |Stirling1(n-2*k,2*k)|/(4^k * k! * (n-2*k)!).
%o A353891 (PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(exp((x*log(1-x))^2/4)))
%o A353891 (PARI) a(n) = n!*sum(k=0, n\4, (2*k)!*abs(stirling(n-2*k, 2*k, 1))/(4^k*k!*(n-2*k)!));
%Y A353891 Cf. A066166, A353892, A353893.
%Y A353891 Cf. A347001, A353880, A353894.
%K A353891 nonn
%O A353891 0,5
%A A353891 _Seiichi Manyama_, May 09 2022