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 A349023 #11 Nov 06 2021 09:09:07
%S A349023 1,2,11,64,417,2892,20941,156500,1198049,9346690,74042938,594001236,
%T A349023 4815995027,39399831458,324840184326,2696343599336,22514057175337,
%U A349023 188977375146888,1593661234493561,13495942411592260,114723671513478118,978570384358686064
%N A349023 G.f. satisfies: A(x) = 1/(1 - x/(1 - x*A(x))^4)^2.
%F A349023 If g.f. satisfies: A(x) = 1/(1 - x/(1 - x*A(x))^s)^t, then a(n) = Sum_{k=0..n} binomial(t*n-(t-1)*(k-1),k) * binomial(n+(s-1)*k-1,n-k)/(n-k+1).
%o A349023 (PARI) a(n, s=4, t=2) = sum(k=0, n, binomial(t*n-(t-1)*(k-1), k)*binomial(n+(s-1)*k-1, n-k)/(n-k+1));
%Y A349023 Cf. A118971, A321798, A349024.
%K A349023 nonn
%O A349023 0,2
%A A349023 _Seiichi Manyama_, Nov 06 2021