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
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
MATHEMATICA
pr=7; Select[Prime[Range[200]], MultiplicativeOrder[pr, # ] == #-1 &]
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved