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 A371228 #9 Mar 16 2024 11:57:21
%S A371228 1,0,2,3,80,510,12084,164640,4272736,91935648,2769703920,80692896240,
%T A371228 2849745645504,103479044628960,4250475820200960,183436357950387360,
%U A371228 8649275730513361920,430735131434242736640,22999938416454315239424,1295673669960473064844800
%N A371228 E.g.f. satisfies A(x) = 1 - x*A(x)*log(1 - x*A(x)^2).
%F A371228 a(n) = n! * Sum_{k=0..floor(n/2)} (2*n-k)! * |Stirling1(n-k,k)|/( (n-k)! * (2*n-2*k+1)! ).
%o A371228 (PARI) a(n) = n!*sum(k=0, n\2, (2*n-k)!*abs(stirling(n-k, k, 1))/((n-k)!*(2*n-2*k+1)!));
%Y A371228 Cf. A371227, A371229, A371230.
%Y A371228 Cf. A371121.
%K A371228 nonn
%O A371228 0,3
%A A371228 _Seiichi Manyama_, Mar 15 2024