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 A371234 #9 Mar 16 2024 11:56:59
%S A371234 1,0,0,6,12,40,4500,36288,302400,21280320,372808800,5690583360,
%T A371234 328776433920,9448800042240,224460513268992,12193757153424000,
%U A371234 487602908139110400,16244434378146723840,899553800205694310400,45212291317983663820800
%N A371234 E.g.f. satisfies A(x) = 1 - x^2*A(x)^4*log(1 - x*A(x)^2).
%F A371234 a(n) = n! * (2*n)! * Sum_{k=0..floor(n/3)} |Stirling1(n-2*k,k)|/( (n-2*k)! * (2*n-k+1)! ).
%o A371234 (PARI) a(n) = n!*(2*n)!*sum(k=0, n\3, abs(stirling(n-2*k, k, 1))/((n-2*k)!*(2*n-k+1)!));
%Y A371234 Cf. A371233, A371235.
%Y A371234 Cf. A371234.
%K A371234 nonn
%O A371234 0,4
%A A371234 _Seiichi Manyama_, Mar 15 2024