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 A379331 #10 Dec 21 2024 11:10:24
%S A379331 1,2,12,100,976,10432,118216,1395200,16965664,211078656,2674095616,
%T A379331 34378044416,447359023072,5881178595328,77992591652992,
%U A379331 1042089880305664,14015275654390272,189583355671740416,2577607282441795840,35205701425533550592,482822120552883164160
%N A379331 G.f. A(x) satisfies A(x) = 1/sqrt( (1 - 2*x*A(x)^3) * (1 - 2*x*A(x)) ).
%F A379331 a(n) = 2^n * Sum_{k=0..n} binomial(n/2+2*k+1/2,k) * binomial(3*n/2-1/2,n-k)/(n+4*k+1).
%o A379331 (PARI) a(n) = 2^n*sum(k=0, n, binomial(n/2+2*k+1/2, k)*binomial(3*n/2-1/2, n-k)/(n+4*k+1));
%Y A379331 Cf. A379329, A379330.
%K A379331 nonn
%O A379331 0,2
%A A379331 _Seiichi Manyama_, Dec 21 2024