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 A073317 #5 Oct 15 2013 22:31:26
%S A073317 2,3,6,7,22,8,74,29,90,30,1207,31,4118,121,466,467,67266,122,236984,
%T A073317 496,7452,1973,3956273,497,1305399,8014,405387,8015,222108532,498,
%U A073317 792121142,127353,1688345,127354,21495390,8511,66695906846,486580
%N A073317 a(n)=Sum_{j = 0..n} binomial(phi(n),phi(j)).
%t A073317 g[x_] := EulerPhi[x] Table[Apply[Plus, Table[Binomial[g[n], g[j]], {j, 0, n}]], {n, 1, 50}]
%Y A073317 Cf. A066781, A073318.
%K A073317 easy,nonn
%O A073317 1,1
%A A073317 _Labos Elemer_, Jul 26 2002