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 A365133 #9 Aug 23 2023 08:36:18
%S A365133 1,2,9,48,284,1792,11816,80446,561186,3990398,28815594,210746538,
%T A365133 1557834174,11620294376,87357498949,661194915408,5034368831334,
%U A365133 38534430714502,296341243824737,2288568585083816,17741278361562738,138006870242288796,1076905750814353045
%N A365133 G.f. satisfies A(x) = (1 + x*A(x)/(1 - x*A(x))^2)^2.
%F A365133 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(n+(s-1)*k-1,n-k).
%o A365133 (PARI) a(n, s=2, t=2) = sum(k=0, n, binomial(t*(n+1), k)*binomial(n+(s-1)*k-1, n-k))/(n+1);
%Y A365133 Cf. A109081, A365134.
%Y A365133 Cf. A365120.
%K A365133 nonn
%O A365133 0,2
%A A365133 _Seiichi Manyama_, Aug 23 2023