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 A364723 #22 Aug 07 2023 07:46:06
%S A364723 1,1,2,8,38,196,1073,6120,35968,216304,1324676,8232981,51796538,
%T A364723 329229344,2111031444,13638557196,88695018723,580153216512,
%U A364723 3814285704000,25192499164320,167075960048996,1112162062296061,7428213584196010,49766086788057256
%N A364723 G.f. satisfies A(x) = 1 + x*A(x) / (1 - x*A(x)^4).
%F A364723 a(n) = (1/n) * Sum_{k=0..n-1} binomial(n,k) * binomial(n+3*k,n-1-k) for n > 0.
%o A364723 (PARI) a(n) = if(n==0, 1, sum(k=0, n-1, binomial(n, k)*binomial(n+3*k, n-1-k))/n);
%Y A364723 Cf. A000108, A106228, A300048, A364734.
%Y A364723 Cf. A364739.
%K A364723 nonn
%O A364723 0,3
%A A364723 _Seiichi Manyama_, Aug 05 2023