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 A384577 #12 Jun 04 2025 09:53:52 %S A384577 1,3,6,19,78,411,2617,19251,160254,1482400,15035622,165545253, %T A384577 1963006576,24908182305,336397711074,4813816122917,72704962269990, %U A384577 1155070280657286,19245587072017468,335418172582313610,6100293082529588802,115532044092709366555,2274095852526512246841 %N A384577 G.f. A(x) satisfies A(x) = ( 1 + x * A(x*A(x))^(1/3) )^3. %F A384577 See A384581. %F A384577 G.f.: B(x)^3, where B(x) is the g.f. of A143501. %o A384577 (PARI) a(n, k=3) = if(k==0, 0^n, k*sum(j=0, n, binomial(3*n-3*j+k, j)/(3*n-3*j+k)*a(n-j, j))); %Y A384577 Column k=3 of A384581. %K A384577 nonn %O A384577 0,2 %A A384577 _Seiichi Manyama_, Jun 04 2025