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 A381601 #7 Mar 01 2025 08:36:16 %S A381601 1,1,7,79,1134,18953,353134,7154751,155181240,3565276582,86122663681, %T A381601 2175366732971,57218428637862,1562164759518688,44156180231275177, %U A381601 1289514761824080659,38840440076269957435,1204858168452465020445,38445264045516464373511 %N A381601 G.f. A(x) satisfies A(x) = 1/(1 - x * A(x)^3 * A(x*A(x)^3)^3). %F A381601 See A381594. %o A381601 (PARI) a(n, k=1) = if(k==0, 0^n, k*sum(j=0, n, binomial(3*n+j+k, j)/(3*n+j+k)*a(n-j, 3*j))); %Y A381601 Column k=1 of A381594. %K A381601 nonn %O A381601 0,3 %A A381601 _Seiichi Manyama_, Mar 01 2025