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 A077096 #18 May 07 2025 05:30:54
%S A077096 7530,8064,9678,9828,9990,10002,10290,10464,11000,11004,11172,11350,
%T A077096 11510,11572,11814,11930,12006,12192,12348,12472,12636,12654,12726,
%U A077096 12750,12772,12972,13332,13372,13420,13440,13626,13648,13656,13695
%N A077096 Numbers k such that iterating phi(sigma(k)-phi(k)) starting from k leads to the fixed point 8064.
%e A077096 n=41354: FixedPointList={41354,13440,15232,8064}, end=8064.
%t A077096 f[x_] := EulerPhi[DivisorSigma[1, x]-EulerPhi[x]] Do[s=NestList[f, n, 100]; s1=Part[s, 99]; s2=Part[s, 100]; If[Equal[s1, s2]&&Equal[s1, 8064], Print[n]], {n, 1, 1000000}]
%t A077096 fp[n_]:=FixedPoint[EulerPhi[DivisorSigma[1,#]-EulerPhi[#]]&,n,100]==8064; Select[ Range[14000],fp] (* _Harvey P. Dale_, May 05 2013 *)
%Y A077096 Cf. A077090, A077091, A077092, A077093, A077094, A077095.
%K A077096 nonn,more
%O A077096 1,1
%A A077096 _Labos Elemer_, Oct 31 2002