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 A096850 #8 Nov 29 2013 14:52:42
%S A096850 1,2,4,6,8,12,16,24,30,48,60,72,96,128,240,432,480,576,720,864,1200,
%T A096850 1280,1512,1536,1728,1800,1860,2016,2560,2880,3024,3456,3840,6912,
%U A096850 10368,14080,15552,15840,18144,27648,30976,32768,34560,41472,42240,48384
%N A096850 Consider iteration of the function f(x) = phi(sigma(x)) = A062401(x). Sequence gives numbers n such that the trajectory of n returns to n.
%H A096850 Charles R Greathouse IV, <a href="/A096850/b096850.txt">Table of n, a(n) for n = 1..110</a>
%e A096850 Examples of cycles: {[1], [2], [4, 6], [8], [12], [16, 30, 24], [48, 60], [72, 96], [128]}.
%e A096850 95 => 32 => 36 => 72 => 96 => 72 => ..., therefore 72 and 96 are in the sequence.
%t A096850 a = {}; f[n_] := EulerPhi[ DivisorSigma[ 1, n]]; Do[ AppendTo[a, NestWhileList[f, n, UnsameQ, All][[ -1]]]; a = Union[a], {n, 10^6}]; Take[ a, 46] (* _Robert G. Wilson v_, Jul 21 2004 *)
%o A096850 (PARI) f(n)=eulerphi(sigma(n))
%o A096850 is(n)=my(t=f(n),h=f(t));while(t!=h,t=f(t);h=f(f(h));if(t==n, return(1)));t==n \\ _Charles R Greathouse IV_, Nov 27 2013
%Y A096850 Cf. A062401, A095952-A095956, A096887-A096890, A096849-A096851.
%K A096850 nonn
%O A096850 1,2
%A A096850 _Labos Elemer_, Jul 16 2004
%E A096850 Edited and extended by _Robert G. Wilson v_, Jul 21 2004