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%I #8 Oct 15 2013 22:31:38
%S 7530,8064,9678,9828,9990,10002,10290,10464,11000,11004,11172,11350,
%T 11510,11572,11814,11930,12006,12192,12348,12472,12636,12654,12726,
%U 12750,12772,12972,13332,13372,13420,13440,13626,13648,13656,13695
%N Starting iteration of Phi[]*(Sigma[]-Phi[]) function at these initial values leads to the fixed point 8064.
%e n=41354: FixedPointList={41354,13440,15232,8064},end=8064.
%t 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 fp[n_]:=FixedPoint[EulerPhi[DivisorSigma[1,#]-EulerPhi[#]]&,n,100]==8064; Select[ Range[14000],fp] (* _Harvey P. Dale_, May 05 2013 *)
%Y Cf. A077090-A077100.
%K nonn
%O 1,1
%A _Labos Elemer_, Oct 31 2002