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 A379159 #9 Dec 17 2024 08:44:54
%S A379159 1,1,3,13,59,294,1548,8473,47694,274347,1605553,9529080,57219636,
%T A379159 346989180,2121996165,13071868062,81039237719,505230120558,
%U A379159 3165528142389,19922166970041,125882558097870,798300369383649,5079196380442687,32413550247722622,207420591733202421
%N A379159 G.f. A(x) satisfies A(x) = (1 + x^3) * (1 + x*A(x)^3).
%F A379159 a(n) = Sum_{k=0..floor(n/3)} binomial(3*n-9*k+1,k) * binomial(3*n-9*k+1,n-3*k)/(3*n-9*k+1).
%o A379159 (PARI) a(n) = sum(k=0, n\3, binomial(3*n-9*k+1, k)*binomial(3*n-9*k+1, n-3*k)/(3*n-9*k+1));
%Y A379159 Cf. A200725, A364336, A379160.
%Y A379159 Cf. A364329.
%K A379159 nonn
%O A379159 0,3
%A A379159 _Seiichi Manyama_, Dec 17 2024