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A377179
Primes p such that -9/2 is a primitive root modulo p.
6
5, 13, 23, 29, 31, 47, 53, 61, 71, 79, 101, 109, 149, 151, 157, 167, 173, 191, 197, 199, 223, 229, 239, 263, 269, 277, 293, 311, 317, 359, 367, 373, 383, 389, 461, 463, 479, 487, 503, 509, 557, 599, 613, 647, 653, 661, 677, 701, 709, 719, 733, 743, 757, 773, 797, 821, 823, 829, 839, 853, 863, 887, 911, 967, 983, 991
OFFSET
1,1
COMMENTS
If p is a term in this sequence, then -9/2 is not a square modulo p (i.e., p is in A003628).
Conjecture: this sequence has relative density equal to Artin's constant (A005596) with respect to the set of primes.
PROG
(PARI) forprime(p=5, 10^3, if(znorder(Mod(-9/2, p))==p-1, print1(p, ", ")));
CROSSREFS
Primes p such that +a/2 is a primitive root modulo p: A320384 (a=3), A377174 (a=5), A377176 (a=7), A377178 (a=9).
Primes p such that -a/2 is a primitive root modulo p: A377172 (a=3), A377175 (a=5), A377177 (a=7), this sequence (a=9).
Sequence in context: A076408 A006353 A155142 * A155552 A219546 A143988
KEYWORD
nonn,easy
AUTHOR
Jianing Song, Oct 18 2024
STATUS
approved