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A300079 Composite numbers n such that there are exactly phi(phi(n)) residues modulo n of the maximum order. 4
4, 6, 9, 10, 14, 15, 16, 18, 20, 22, 25, 26, 27, 30, 32, 34, 35, 38, 39, 40, 45, 46, 48, 49, 50, 51, 52, 54, 55, 58, 60, 62, 64, 68, 70, 74, 75, 78, 81, 82, 85, 86, 87, 90, 94, 95, 96, 98, 100, 102, 104, 105, 106, 110, 111, 112, 115, 116, 118, 119, 120, 121, 122, 123, 125, 128, 134, 135, 136, 140, 142, 143, 144, 146, 148, 150, 153 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Composite numbers n such that A111725(n) = A010554(n).

Contains as a subsequence the nontrivial prime powers (A246547) except 2^3 = 8.

LINKS

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

CROSSREFS

Subsequence of A300064.

Set difference of A002808 and A300065.

Contains A300080 as a subsequence.

Cf. A002322, A010554, A111725.

Sequence in context: A284654 A010428 A189300 * A233182 A028260 A085155

Adjacent sequences:  A300076 A300077 A300078 * A300080 A300081 A300082

KEYWORD

nonn

AUTHOR

Max Alekseyev, Feb 24 2018

STATUS

approved

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Last modified May 9 05:03 EDT 2021. Contains 343688 sequences. (Running on oeis4.)