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 A372746 #6 May 12 2024 10:04:20 %S A372746 0,1,1,-1,3,-5,-140,3265,-35145,-423300,29156450,-244674300, %T A372746 -35711239900,1323533263450,79091925545150,-7803803198306500, %U A372746 -249393437031632750,68360119098495114000,386044168785212367500,-899401682046014451577000 %N A372746 E.g.f. A(x) satisfies A(A(A(A(A(x))))) = (exp(5*x) - 1)/5. %F A372746 Define the sequence b(n,m) as follows. If n<m, b(n,m) = 0, else if n=m, b(n,m) = 1, otherwise b(n,m) = 1/5 * ( 5^(n-m) * Stirling2(n,m) - Sum_{l=m+1..n-1} (b(n,l) + Sum_{k=l..n} (b(n,k) + Sum_{j=k..n} (b(n,j) + Sum_{i=j..n} b(n,i) * b(i,j)) * b(j,k)) * b(k,l)) * b(l,m) ). a(n) = b(n,1). %Y A372746 Cf. A184011, A209519. %K A372746 sign %O A372746 0,5 %A A372746 _Seiichi Manyama_, May 12 2024