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 A379185 #6 Dec 18 2024 09:27:51
%S A379185 1,3,18,139,1222,11618,116372,1209779,12930966,141225530,1569136588,
%T A379185 17680779230,201562070356,2320574126216,26942875644408,
%U A379185 315109464849603,3708926665685286,43901133108206978,522240410257549260,6240258006163094026,74864641626913850964
%N A379185 G.f. A(x) satisfies A(x) = 1/((1 - x*A(x)^2) * (1 - x*A(x))^2).
%F A379185 a(n) = Sum_{k=0..n} binomial(n+2*k+1,k) * binomial(3*n+k+1,n-k)/(n+2*k+1).
%o A379185 (PARI) a(n) = sum(k=0, n, binomial(n+2*k+1, k)*binomial(3*n+k+1, n-k)/(n+2*k+1));
%Y A379185 Cf. A006632, A369616, A379186.
%K A379185 nonn
%O A379185 0,2
%A A379185 _Seiichi Manyama_, Dec 17 2024