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 A371617 #12 Mar 30 2024 01:41:35
%S A371617 1,2,7,54,419,3644,33366,317672,3113559,31200060,318219653,3292546660,
%T A371617 34475311605,364621943538,3889561661610,41799988930926,
%U A371617 452126713579192,4918321519144206,53773399008883695,590578523863692086,6512515698908748358
%N A371617 G.f. satisfies A(x) = ( 1 + x / (1 - x*A(x)^3)^3 )^2.
%H A371617 Seiichi Manyama, <a href="/A371617/b371617.txt">Table of n, a(n) for n = 0..934</a>
%F A371617 a(n) = Sum_{k=0..n} binomial(6*(n-k)+2,k) * binomial(n+2*k-1,n-k)/(3*(n-k)+1).
%o A371617 (PARI) a(n, r=2, s=3, t=0, u=6) = 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 A371617 Cf. A371613, A371615.
%Y A371617 Cf. A371616.
%K A371617 nonn
%O A371617 0,2
%A A371617 _Seiichi Manyama_, Mar 29 2024