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 A384941 #9 Jun 13 2025 08:21:13 %S A384941 1,1,4,-2,-64,-95,780,5230,19228,-90488,-1454232,-4080620,19557280, %T A384941 270109125,1702743364,-35378580,-74674412048,-515950535521, %U A384941 -1719717134140,9100931191804,173629815007712,988336433707663,2065106985108344,-25897495149473592 %N A384941 G.f. A(x) satisfies A(x) = 1 + x/A(-x*A(x))^4. %F A384941 See A384944. %o A384941 (PARI) a(n, k=-1) = if(n*k==0, 0^n, (-1)^n*k*sum(j=1, n, binomial(-n+2*j+k-1, j-1)*a(n-j, 4*j)/j)); %Y A384941 Column k=1 of A384944. %Y A384941 Cf. A002293, A213101, A213102, A213103. %Y A384941 Cf. A000012, A384894, A384896, A384942, A384943. %K A384941 sign %O A384941 0,3 %A A384941 _Seiichi Manyama_, Jun 13 2025