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A067573 Numbers such that Sigma(Phi(k))/Sigma(k) > Sigma(Phi(j))/Sigma(j) for all k > j. 2
2, 3, 5, 7, 13, 31, 37, 61, 181, 241, 421, 1009, 1201, 1321, 1801, 2161, 2521, 7561, 12601, 15121, 30241, 55441, 110881, 278263, 332641, 555911, 666917, 722473, 1443853, 2165407, 3607403, 4324321, 7212581, 8654539, 10817761, 21631147 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
MATHEMATICA
a = 0; Do[b = DivisorSigma[1, EulerPhi[n]]/DivisorSigma[1, n]; If[b > a, a = b; Print[n]], {n, 2, 10^7}]
CROSSREFS
Sequence in context: A071905 A306317 A359483 * A103199 A054217 A355521
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Jan 30 2002
STATUS
approved

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Last modified March 29 04:23 EDT 2024. Contains 371264 sequences. (Running on oeis4.)