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 A375237 #20 Sep 01 2024 10:13:29
%S A375237 1,0,0,6,0,30,540,420,15120,192780,623700,15467760,187110000,
%T A375237 1394593200,30353483160,401350950000,4974611241600,105201040744800,
%U A375237 1624218256861200,27525899782180800,599214125325816000,10967831645346576000,227431647445400798400
%N A375237 Expansion of e.g.f. 1 / (1 + x * log(1 - x^2/2))^2.
%F A375237 E.g.f.: B(x)^2, where B(x) is the e.g.f. of A375167.
%F A375237 a(n) = n! * Sum_{k=0..floor(n/2)} (n-2*k+1)! * |Stirling1(k,n-2*k)|/(2^k*k!).
%o A375237 (PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(1/(1+x*log(1-x^2/2))^2))
%o A375237 (PARI) a(n) = n!*sum(k=0, n\2, (n-2*k+1)!*abs(stirling(k, n-2*k, 1))/(2^k*k!));
%Y A375237 Cf. A375167, A375682.
%K A375237 nonn
%O A375237 0,4
%A A375237 _Seiichi Manyama_, Aug 23 2024