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A077083
Length of iteration until fixed point is reached when Phi[Sigma[n]+phi(n)]=A077080 is iterated with initial value of n.
2
1, 1, 2, 2, 3, 1, 2, 16, 16, 1, 2, 16, 17, 17, 16, 15, 16, 15, 16, 1, 2, 1, 2, 14, 14, 16, 15, 14, 15, 14, 15, 13, 14, 15, 15, 10, 11, 15, 14, 13, 14, 11, 12, 2, 14, 1, 2, 1, 12, 6, 2, 12, 13, 3, 2, 2, 3, 1, 2, 11, 12, 11, 2, 11, 14, 10, 11, 13, 2, 2, 3, 5, 6, 14, 10, 10, 2, 12, 13, 9
OFFSET
1,3
FORMULA
a(n)=Length[FixedPointList[A077080, n]]-1.
EXAMPLE
n=1,2,6,10,..864: a[n]=1, n is fixed point for some n; n=225: results in iteration sequence of 44 terms: {225,522,444,...,471744,653312,570240}, 44=a[225].
MATHEMATICA
f[x_] := EulerPhi[DivisorSigma[1, x]+EulerPhi[x]] Table[Length[FixedPointList[f, w]]-1, {w, 1, 1024}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Oct 28 2002
STATUS
approved