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 A096989 #3 Oct 15 2013 22:32:33 %S A096989 5,7,8,9,10,11,12,14,18,22,37,43,49,51,53,57,61,63,64,65,67,68,71,73, %T A096989 74,76,77,79,80,81,83,85,86,87,89,91,93,95,96,97,98,99,101,102,103, %U A096989 104,105,106,107,108,109,111,112,113,114,115,116,117,119,120,121,122,123,124 %N A096989 Initial values for f(x)=sigma(phi[x])=A062402[x] such that iteration of f ends in cycle of length=2. %Y A096989 Cf. A062402, A095953. %K A096989 nonn %O A096989 1,1 %A A096989 _Labos Elemer_, Jul 19 2004