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 A096988 #9 Dec 15 2016 08:18:37
%S A096988 1,2,3,4,6,13,15,16,20,21,23,24,25,26,28,30,33,36,42,44,46,50,66,157,
%T A096988 169,203,215,237,241,245,255,256,261,272,275,287,303,305,314,316,320,
%U A096988 325,338,340,344,347,367,369,375,384,385,392,393,404,406,408,429,430
%N A096988 Initial values for f(x)=sigma(phi(x))=A062402(x) such that iteration of f ends in cycle of length=1.
%H A096988 Ivan Neretin, <a href="/A096988/b096988.txt">Table of n, a(n) for n = 1..10000</a>
%t A096988 a = {}; Do[s = {n}; While[! MemberQ[s, k = DivisorSigma[1, EulerPhi[s[[-1]]]]], AppendTo[s, k]]; If[s[[-1]] == k, AppendTo[a, n]], {n, 430}]; a (* _Ivan Neretin_, Dec 15 2016 *)
%Y A096988 Cf. A062402, A095952, A018784.
%K A096988 nonn
%O A096988 1,2
%A A096988 _Labos Elemer_, Jul 19 2004