OFFSET
1,2
EXAMPLE
n=30: FixedPointList={30,32,46,20,16,22,12,8,10,6,4},end=4; n=94:FixedPointList={94,42,24},end=24.
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]&&!PrimeQ[n], Print[{n, s1}]], {n, 1, 1000}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Oct 31 2002
STATUS
approved