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 A365130 #9 Aug 23 2023 08:34:25
%S A365130 1,3,18,124,945,7650,64592,562419,5013645,45530725,419735784,
%T A365130 3917714430,36949853641,351597275136,3371317098546,32542166997655,
%U A365130 315962469096855,3083729075615055,30236064140642514,297698542934231016,2942082095638037148
%N A365130 G.f. satisfies A(x) = (1 + x*A(x)*(1 + x*A(x))^2)^3.
%F A365130 If g.f. satisfies A(x) = (1 + x*A(x)*(1 + x*A(x))^s)^t, then a(n) = (1/(n+1)) * Sum_{k=0..n} binomial(t*(n+1),k) * binomial(s*k,n-k).
%o A365130 (PARI) a(n, s=2, t=3) = sum(k=0, n, binomial(t*(n+1), k)*binomial(s*k, n-k))/(n+1);
%Y A365130 Cf. A161634, A365129.
%Y A365130 Cf. A137953.
%K A365130 nonn
%O A365130 0,2
%A A365130 _Seiichi Manyama_, Aug 23 2023