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 A143638 #9 Dec 20 2014 13:49:28
%S A143638 1,1,3,34,605,16416,644647,33690574,2252245353,187575203080,
%T A143638 19000833293771,2295318297423834,325536649109809117,
%U A143638 53508774130762119508,10080999100649218887615,2156137639664134179951166,519200838601168582073365073,139740129055162031424178122096
%N A143638 E.g.f. satisfies: A(x) = exp(x*A(((x+1)^7-1)/7)).
%H A143638 Alois P. Heinz, <a href="/A143638/b143638.txt">Table of n, a(n) for n = 0..100</a>
%p A143638 A:= proc(n,k::nonnegint) option remember; if n<=0 or k=0 then 1 else A(n-1,k)(((x+1)^k-1)/k) fi; unapply(convert(series(exp(x*%), x,n+1), polynom), x) end: a:= n-> coeff(A(n,7)(x), x,n)*n!: seq(a(n), n=0..20);
%t A143638 A[n_, k_] := Module[{f}, f[x_] = If[n <= 0 || k == 0, 1, A[n-1, k][((x+1)^k-1)/k]]; Normal[Series[Exp[x*f[x]], { x, 0, n+1}]] /. x -> #]&; a[n_] := Coefficient[A[n, 7][x], x, n]*n!; Table[a[n], {n, 0, 21}] (* _Jean-François Alcover_, Feb 14 2014, after Maple *)
%Y A143638 Cf. 7th column of A143632.
%K A143638 nonn
%O A143638 0,3
%A A143638 _Alois P. Heinz_, Aug 27 2008