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 A375806 #12 Sep 01 2024 10:49:33
%S A375806 1,2,6,30,192,1520,14220,153720,1881600,25728192,388402560,6415960320,
%T A375806 115078138560,2227056923520,46247253212160,1025696098627200,
%U A375806 24195406204569600,604862279807385600,15973029429800002560,444299711254300661760,12983645995613669376000
%N A375806 Expansion of e.g.f. 1/(1 + (log(1 - x^2))/x)^2.
%F A375806 E.g.f.: B(x)^2, where B(x) is the e.g.f. of A375798.
%F A375806 a(n) = n! * Sum_{k=0..floor(n/2)} (n-2*k+1)! * |Stirling1(n-k,n-2*k)|/(n-k)!.
%o A375806 (PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(1/(1+log(1-x^2)/x)^2))
%o A375806 (PARI) a(n) = n!*sum(k=0, n\2, (n-2*k+1)!*abs(stirling(n-k, n-2*k, 1))/(n-k)!);
%Y A375806 Cf. A375798, A375807.
%Y A375806 Cf. A375680.
%K A375806 nonn
%O A375806 0,2
%A A375806 _Seiichi Manyama_, Aug 29 2024