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A072302 Number of positive integers not exceeding n that are relatively prime to phi(n). 0
1, 2, 2, 2, 3, 3, 3, 4, 3, 5, 5, 6, 5, 5, 8, 8, 9, 6, 7, 10, 7, 9, 11, 12, 10, 9, 9, 9, 13, 15, 9, 16, 14, 17, 12, 12, 13, 13, 13, 20, 17, 14, 13, 18, 15, 21, 23, 24, 14, 20, 26, 17, 25, 18, 22, 19, 19, 25, 29, 30, 17, 17, 21, 32, 22, 26, 21, 34, 32, 23, 25, 24, 25, 25, 30, 25, 21 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..77.

EXAMPLE

Among the positive integers not exceeding 12, the six numbers 1,3,5,7,9,11 are relatively prime to phi(12)=4. Hence a(12)=6.

MATHEMATICA

r = {}; Do[s = EulerPhi[n]; j = 0; For[i = 1, i <= n, i++, If[GCD[s, i] == 1, j++ ]]; r = Append[r, j], {n, 1, 10^2}]; r

CROSSREFS

Sequence in context: A112754 A283467 A045864 * A165360 A340542 A283303

Adjacent sequences:  A072299 A072300 A072301 * A072303 A072304 A072305

KEYWORD

nonn

AUTHOR

Joseph L. Pe, Jul 14 2002

STATUS

approved

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Last modified May 13 19:36 EDT 2021. Contains 343868 sequences. (Running on oeis4.)