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 A371613 #11 Mar 30 2024 02:36:32
%S A371613 1,2,3,16,83,460,2767,17210,110308,723624,4832363,32747106,224619408,
%T A371613 1556484636,10879744696,76621739626,543159825499,3872610857558,
%U A371613 27752175177823,199787917082084,1444171829169939,10477887409768628,76275565075016394
%N A371613 G.f. satisfies A(x) = ( 1 + x / (1 - x*A(x)^3) )^2.
%F A371613 a(n) = Sum_{k=0..n} binomial(6*(n-k)+2,k) * binomial(n-1,n-k)/(3*(n-k)+1).
%o A371613 (PARI) a(n, r=2, s=1, 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 A371613 Cf. A371615, A371617.
%Y A371613 Cf. A365118, A371612.
%K A371613 nonn
%O A371613 0,2
%A A371613 _Seiichi Manyama_, Mar 29 2024