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 A371227 #8 Mar 16 2024 11:57:32
%S A371227 1,0,2,3,56,390,6384,92400,1812768,38565072,949927680,25934040000,
%T A371227 783458550720,25909868761920,930720395219328,36108805836317760,
%U A371227 1504050682102456320,66964478742976711680,3173178938051223889920,159461567895099436047360
%N A371227 E.g.f. satisfies A(x) = 1 - x*log(1 - x*A(x)^2).
%F A371227 a(n) = n! * Sum_{k=0..floor(n/2)} (2*n-2*k)! * |Stirling1(n-k,k)|/( (n-k)! * (2*n-3*k+1)! ).
%o A371227 (PARI) a(n) = n!*sum(k=0, n\2, (2*n-2*k)!*abs(stirling(n-k, k, 1))/((n-k)!*(2*n-3*k+1)!));
%Y A371227 Cf. A371228, A371229, A371230.
%Y A371227 Cf. A371117.
%K A371227 nonn
%O A371227 0,3
%A A371227 _Seiichi Manyama_, Mar 15 2024