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 A384975 #7 Jun 14 2025 10:36:34 %S A384975 1,1,4,16,77,303,718,-4934,-108553,-1275290,-12473324,-107472840, %T A384975 -826679323,-5418440094,-24911021972,28733788740,2764189150143, %U A384975 48003187278203,629585195050804,7164019744705726,73396269512625553,677866973062726837,5460528984809591552 %N A384975 G.f. A(x) satisfies A(x) = 1 + x*A(x)/A(-x*A(x)^5)^3. %F A384975 See A384978. %o A384975 (PARI) a(n, k=-1) = if(n*k==0, 0^n, (-1)^n*k*sum(j=1, n, binomial(-5*n+5*j+k-1, j-1)*a(n-j, 3*j)/j)); %Y A384975 Column k=1 of A384978. %K A384975 sign %O A384975 0,3 %A A384975 _Seiichi Manyama_, Jun 14 2025