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 A384809 #10 Jun 10 2025 16:33:25 %S A384809 1,1,5,25,153,-799,-82787,-2990343,-98020367,-2473062911,-22379003019, %T A384809 3535310560409,426542722323721,33942691393940577,2320589389274335117, %U A384809 131491185267395291641,4583444982950062321377,-254657491559719266483967,-86887910247671284788294683 %N A384809 E.g.f. A(x) satisfies A(x) = exp( x/A(-x*A(x)^2)^2 ). %F A384809 See A384811. %o A384809 (PARI) a(n, k=-1) = if(n*k==0, 0^n, (-1)^n*k*sum(j=1, n, (-2*n+2*j+k)^(j-1)*binomial(n, j)*a(n-j, 2*j))); %Y A384809 Column k=1 of A384811. %Y A384809 Cf. A052750, A213110, A213111, A384617, A384810. %K A384809 sign %O A384809 0,3 %A A384809 _Seiichi Manyama_, Jun 10 2025