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 A379279 #9 Dec 20 2024 02:47:48
%S A379279 1,4,30,288,3125,36490,447478,5683186,74105002,986302778,13344661479,
%T A379279 182998935930,2537838036761,35530970858236,501523116910044,
%U A379279 7129275916213606,101973703002773268,1466574750062589956,21194869324964207133,307642575576365729486,4482940969372057898247
%N A379279 G.f. A(x) satisfies A(x) = ( (1 + x*A(x)^2) * (1 + x*A(x)) )^2.
%F A379279 G.f.: B(x)^2 where B(x) is the g.f. of A215715.
%F A379279 a(n) = Sum_{k=0..n} binomial(2*n+2*k+2,k) * binomial(2*n+2*k+2,n-k)/(n+k+1).
%o A379279 (PARI) a(n) = sum(k=0, n, binomial(2*n+2*k+2, k)*binomial(2*n+2*k+2, n-k)/(n+k+1));
%Y A379279 Cf. A371675, A379251, A379282.
%Y A379279 Cf. A073155, A379280.
%Y A379279 Cf. A215715.
%K A379279 nonn
%O A379279 0,2
%A A379279 _Seiichi Manyama_, Dec 19 2024