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A077096 Starting iteration of Phi[]*(Sigma[]-Phi[]) function at these initial values leads to the fixed point 8064. 0
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 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
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
Sequence in context: A273382 A186938 A185749 * A031137 A210171 A234987
KEYWORD
nonn
AUTHOR
Labos Elemer, Oct 31 2002
STATUS
approved

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Last modified March 1 22:23 EST 2024. Contains 370443 sequences. (Running on oeis4.)