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A077082 Largest value arising when Phi[Sigma[n]+phi(n)]=A077080 is iterated with initial value of n. 1
1, 2, 3, 6, 6, 6, 7, 1044, 1044, 10, 11, 1044, 1044, 1044, 1044, 1044, 1044, 1044, 1044, 20, 21, 22, 23, 1044, 1044, 1044, 1044, 1044, 1044, 1044, 1044, 1044, 1044, 1044, 1044, 1044, 1044, 1044, 1044, 1044, 1044, 1044, 1044, 48, 1044, 46, 47, 48, 1044 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..49.

FORMULA

a(n)=Max[FixedPointList[A077080, n]]. See program below. Seems convergent.[tested for initial values below 1024.

EXAMPLE

n=225: results in iteration sequence of 44 terms: {225,522,444,...,471744,653312,570240}, largest is 653312=a[25].

MATHEMATICA

f[x_] := EulerPhi[DivisorSigma[1, x]+EulerPhi[x]] Table[Max[FixedPointList[f, w]], {w, 1, 1024}]

CROSSREFS

Cf. A000010, A000203, A065387, A077080-A077085.

Sequence in context: A290223 A274213 A078706 * A333936 A193896 A099162

Adjacent sequences:  A077079 A077080 A077081 * A077083 A077084 A077085

KEYWORD

nonn

AUTHOR

Labos Elemer, Oct 28 2002

STATUS

approved

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Last modified December 6 13:24 EST 2021. Contains 349563 sequences. (Running on oeis4.)