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 A084207 #7 Jul 26 2018 17:42:24
%S A084207 1,1,-2,8,-34,158,-768,3858,-19851,104023,-552974,2973832,-16146688,
%T A084207 88376636,-487034106,2699839758,-15043262970,84197804254,
%U A084207 -473140314356,2668221663736,-15095165871964,85645090974518,-487190919969502
%N A084207 G.f. A(x) defined by: A(x)^7 consists entirely of integer coefficients between 1 and 7 (A083947); A(x) is the unique power series solution with A(0)=1.
%C A084207 Limit a(n)/a(n+1) -> r = -0.166670835025545 where A(r)=0.
%t A084207 kmax = 25;
%t A084207 A[x_] = Sum[a[k] x^k, {k, 0, kmax}];
%t A084207 coes = CoefficientList[A[x]^7 + O[x]^(kmax + 1), x];
%t A084207 r = {a[0] -> 1, a[1] -> 1};
%t A084207 coes = coes /. r;
%t A084207 Do[r = Flatten @ Append[r, Reduce[1 <= coes[[k]] <= 7, a[k-1], Integers] // ToRules];
%t A084207 coes = coes /. r, {k, 3, kmax + 1}];
%t A084207 Table[a[k], {k, 0, kmax}] /. r (* _Jean-François Alcover_, Jul 26 2018 *)
%Y A084207 Cf. A083947, A084202-A084206, A084208-A084212.
%K A084207 sign
%O A084207 0,3
%A A084207 _Paul D. Hanna_, May 20 2003