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 A366676 #8 Oct 16 2023 09:27:49
%S A366676 1,1,3,13,58,288,1512,8250,46296,265491,1548976,9165156,54865737,
%T A366676 331694167,2022232068,12419023617,76755164643,477049187268,
%U A366676 2979758649996,18695276174079,117766227611046,744527923478730,4722464911515423,30044091589750350
%N A366676 G.f. satisfies A(x) = 1 + x^3 + x*A(x)^3.
%F A366676 a(n) = Sum_{k=0..floor(n/3)} binomial(2*(n-3*k)+1,k) * binomial(3*(n-3*k),n-3*k)/(2*(n-3*k)+1).
%o A366676 (PARI) a(n) = sum(k=0, n\3, binomial(2*(n-3*k)+1, k)*binomial(3*(n-3*k), n-3*k)/(2*(n-3*k)+1));
%Y A366676 Cf. A176697, A366677.
%Y A366676 Cf. A366266, A366555.
%K A366676 nonn
%O A366676 0,3
%A A366676 _Seiichi Manyama_, Oct 16 2023