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A019337
Primes with primitive root 7.
8
2, 5, 11, 13, 17, 23, 41, 61, 67, 71, 79, 89, 97, 101, 107, 127, 151, 163, 173, 179, 211, 229, 239, 241, 257, 263, 269, 293, 347, 349, 359, 379, 397, 431, 433, 443, 461, 491, 499, 509, 521, 547, 577, 593, 599, 601, 631, 659, 677, 683, 733, 739, 743, 761, 773, 797, 823
OFFSET
1,1
COMMENTS
To allow primes less than the specified primitive root m (here, 7) to be included, we use the essentially equivalent definition "Primes p such that the multiplicative order of m mod p is p-1". This comment applies to all of A019334-A019421. - N. J. A. Sloane, Dec 03 2019
All terms apart from the first are == 5, 11, 13, 15, 17, 23 (mod 28) since 7 is a quadratic residue modulo any other prime. By Artin's conjecture, this sequence contains about 37.395% of all primes, that is, about 74.79% of all primes == 5, 11, 13, 15, 17, 23 (mod 28). - Jianing Song, Sep 05 2018
MATHEMATICA
pr=7; Select[Prime[Range[200]], MultiplicativeOrder[pr, # ] == #-1 &]
CROSSREFS
Cf. A167795.
Sequence in context: A066149 A215423 A019387 * A086518 A156672 A145669
KEYWORD
nonn
STATUS
approved