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 A384895 #9 Jun 12 2025 10:23:24 %S A384895 1,1,2,3,4,-3,-50,-237,-872,-2375,-3522,11383,140170,830999,3797676, %T A384895 13901117,36231696,12991001,-656219096,-5809148691,-35189341480, %U A384895 -173155983991,-699938697650,-2079618264082,-1460269315332,39890883936437,413233629798312,2857552649413347 %N A384895 G.f. A(x) satisfies A(x) = 1 + x/A(-x*A(x)^2)^2. %F A384895 See A384900. %o A384895 (PARI) a(n, k=-1) = if(n*k==0, 0^n, (-1)^n*k*sum(j=1, n, binomial(-2*n+3*j+k-1, j-1)*a(n-j, 2*j)/j)); %Y A384895 Column k=1 of A384900. %Y A384895 Cf. A000108, A213094, A213095, A384894. %K A384895 sign %O A384895 0,3 %A A384895 _Seiichi Manyama_, Jun 12 2025