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 A370480 #14 Mar 31 2024 08:45:59
%S A370480 1,3,15,73,360,1800,9112,46632,240936,1255336,6589080,34811784,
%T A370480 184990568,988156872,5303039256,28579068520,154605138984,839272725864,
%U A370480 4570409517848,24961191298248,136688674353000,750355591919240,4128471397725336,22762905189252264
%N A370480 G.f. satisfies A(x) = ( 1 + x * (A(x)^(1/3) / (1-x))^2 )^3.
%F A370480 G.f.: B(x)^3 where B(x) is the g.f. of A006319.
%F A370480 a(n) = 3 * Sum_{k=0..n} binomial(2*k+3,k) * binomial(n+k-1,n-k)/(2*k+3).
%o A370480 (PARI) my(N=30, x='x+O('x^N)); Vec((1+x*((1-x-sqrt(1-6*x+x^2))/(2*x))^2)^3)
%o A370480 (PARI) a(n, r=3, s=2, t=2, u=0) = r*sum(k=0, n, binomial(t*k+u*(n-k)+r, k)*binomial(n+(s-1)*k-1, n-k)/(t*k+u*(n-k)+r));
%Y A370480 Cf. A058396, A370478.
%Y A370480 Cf. A006319, A370479.
%K A370480 nonn
%O A370480 0,2
%A A370480 _Seiichi Manyama_, Mar 31 2024