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 A384649 #9 Jun 06 2025 08:35:57 %S A384649 1,1,2,9,56,432,3935,40820,471633,5980210,82329140,1220547845, %T A384649 19359684220,326799737576,5844913732057,110341722975077, %U A384649 2191461358459051,45656013573862832,995196646595460516,22644288881875546322,536706817952488705651,13225669497771610891404 %N A384649 G.f. A(x) satisfies A(x) = 1/( 1 - x*A(x*A(x)^4) ). %F A384649 See A384653. %o A384649 (PARI) a(n, k=1) = if(k==0, 0^n, k*sum(j=0, n, binomial(4*n-3*j+k, j)/(4*n-3*j+k)*a(n-j, j))); %Y A384649 Column k=1 of A384653. %Y A384649 Cf. A110447, A162661, A384145, A384650. %K A384649 nonn %O A384649 0,3 %A A384649 _Seiichi Manyama_, Jun 06 2025