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 A371892 #8 Apr 11 2024 10:10:14
%S A371892 1,2,4,24,112,688,4032,25856,165888,1103616,7412480,50699776,
%T A371892 350087168,2444208128,17198686208,121945948160,870026493952,
%U A371892 6242802761728,45016506564608,326071359897600,2371312632397824,17307835567636480,126743329792327680
%N A371892 G.f. A(x) satisfies A(x) = 1 + x/A(x) * (1 + A(x)^4).
%F A371892 a(n) = (-1)^(n-1) * (1/n) * Sum_{k=0..n} binomial(n,k) * binomial(2*n-4*k-2,n-1) for n > 0.
%o A371892 (PARI) a(n) = if(n==0, 1, (-1)^(n-1)*sum(k=0, n, binomial(n, k)*binomial(2*n-4*k-2, n-1))/n);
%Y A371892 Cf. A112478, A348957, A364394, A364395, A366363.
%K A371892 nonn
%O A371892 0,2
%A A371892 _Seiichi Manyama_, Apr 11 2024