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 A367059 #10 Nov 04 2023 10:12:10
%S A367059 1,1,3,13,61,309,1651,9153,52161,303681,1798459,10800237,65614237,
%T A367059 402544597,2490398139,15519350593,97326638145,613786324353,
%U A367059 3890080513395,24764386415821,158281551244029,1015314894877237,6534249237530115,42178452056044929
%N A367059 G.f. satisfies A(x) = 1 + x*A(x)^3 + x^3*A(x)^3.
%F A367059 a(n) = Sum_{k=0..floor(n/3)} binomial(2*n-3*k+1,k) * binomial(3*n-6*k,n-3*k)/(2*n-3*k+1).
%o A367059 (PARI) a(n) = sum(k=0, n\3, binomial(2*n-3*k+1, k)*binomial(3*n-6*k, n-3*k)/(2*n-3*k+1));
%Y A367059 Cf. A366676, A367057, A367058, A367060, A367061, A367062.
%K A367059 nonn
%O A367059 0,3
%A A367059 _Seiichi Manyama_, Nov 04 2023