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 A365118 #11 Dec 09 2024 11:17:41
%S A365118 1,2,3,8,23,72,237,808,2830,10118,36779,135510,504935,1899494,7204238,
%T A365118 27517766,105761937,408715018,1587169591,6190357852,24238696551,
%U A365118 95244997612,375469654543,1484519159122,5885302251250,23389997790804,93172394487012
%N A365118 G.f. satisfies A(x) = (1 + x / (1 - x*A(x)))^2.
%F A365118 If g.f. satisfies A(x) = (1 + x/(1 - x*A(x))^s)^t, then a(n) = Sum_{k=0..n} binomial(t*(n-k+1),k) * binomial(n+(s-1)*k-1,n-k)/(n-k+1).
%F A365118 G.f.: A(x) = (1 + x*B(x))^2 where B(x) is the g.f. of A161634. - _Seiichi Manyama_, Dec 09 2024
%o A365118 (PARI) a(n, s=1, t=2) = sum(k=0, n, binomial(t*(n-k+1), k)*binomial(n+(s-1)*k-1, n-k)/(n-k+1));
%Y A365118 Cf. A001006, A365119.
%Y A365118 Cf. A161634, A378801.
%K A365118 nonn
%O A365118 0,2
%A A365118 _Seiichi Manyama_, Aug 22 2023