A077096 Starting iteration of Phi[]*(Sigma[]-Phi[]) function at these initial values leads to the fixed point 8064.

7530, 8064, 9678, 9828, 9990, 10002, 10290, 10464, 11000, 11004, 11172, 11350, 11510, 11572, 11814, 11930, 12006, 12192, 12348, 12472, 12636, 12654, 12726, 12750, 12772, 12972, 13332, 13372, 13420, 13440, 13626, 13648, 13656, 13695

Offset

1,1

Links

Table of n, a(n) for n=1..34.

Example

n=41354: FixedPointList={41354,13440,15232,8064},end=8064.

Mathematica

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}]
fp[n_]:=FixedPoint[EulerPhi[DivisorSigma[1, #]-EulerPhi[#]]&, n, 100]==8064; Select[ Range[14000], fp] (* Harvey P. Dale, May 05 2013 *)

Crossrefs

Cf. A077090-A077100.

Sequence in context: A273382 A186938 A185749 * A031137 A380994 A210171

Adjacent sequences: A077093 A077094 A077095 * A077097 A077098 A077099

Keyword

nonn

Author

Labos Elemer, Oct 31 2002

Status

approved