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A077082
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Largest value arising when Phi[Sigma[n]+phi(n)]=A077080 is iterated with initial value of n.
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1
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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
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OFFSET
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1,2
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LINKS
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FORMULA
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a(n)=Max[FixedPointList[A077080, n]]. See program below. Seems convergent.[tested for initial values below 1024.
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EXAMPLE
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n=225: results in iteration sequence of 44 terms: {225,522,444,...,471744,653312,570240}, largest is 653312=a[25].
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MATHEMATICA
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f[x_] := EulerPhi[DivisorSigma[1, x]+EulerPhi[x]] Table[Max[FixedPointList[f, w]], {w, 1, 1024}]
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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