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 A375798 #10 Aug 29 2024 11:24:39
%S A375798 1,1,2,9,48,340,2820,27720,309120,3897936,54472320,838918080,
%T A375798 14080651200,256214724480,5018771197440,105361754097600,
%U A375798 2358985057228800,56124276848640000,1413738138502609920,37591686093776855040,1052149579611011481600
%N A375798 Expansion of e.g.f. 1/(1 + (log(1 - x^2))/x).
%F A375798 a(n) = n! * Sum_{k=0..floor(n/2)} (n-2*k)! * |Stirling1(n-k,n-2*k)|/(n-k)!.
%o A375798 (PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(1/(1+log(1-x^2)/x)))
%o A375798 (PARI) a(n) = n!*sum(k=0, n\2, (n-2*k)!*abs(stirling(n-k, n-2*k, 1))/(n-k)!);
%Y A375798 Cf. A007840, A375799.
%Y A375798 Cf. A121452.
%K A375798 nonn
%O A375798 0,3
%A A375798 _Seiichi Manyama_, Aug 29 2024