A379161 Primes p such that the multiplicative order of 7 modulo p is prime.

19, 29, 47, 59, 83, 167, 223, 227, 311, 367, 383, 389, 419, 439, 467, 479, 503, 563, 587, 607, 653, 719, 809, 839, 887, 971, 983, 1123, 1307, 1319, 1447, 1487, 1543, 1733, 1811, 1823, 1907, 1997, 2063, 2099, 2153, 2239, 2383, 2579, 2741, 2801, 2819, 2837, 2887, 2903, 2909, 2999, 3023, 3083, 3167, 3463, 3547

Offset

1,1

Comments

Odd primes that divide 7^p-1 for some prime p [after Robert Israel].

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Maple

filter:= n -> isprime(n) and isprime(numtheory:-order(7, n)):
select(filter, [2, 3, 5, seq(i, i=11..10000, 2)]); # Robert Israel, Jan 03 2025

Mathematica

Select[Prime@Range@4000, PrimeQ@MultiplicativeOrder[7, #]&]

Prog

(Magma) [p: p in PrimesInInterval(2, 4000) | IsPrime(Modorder(7, p))];

Crossrefs

Cf. A000040, A122094, A277048, A277049.

Sequence in context: A063644 A156782 A347366 * A092600 A106124 A062679

Adjacent sequences: A379158 A379159 A379160 * A379162 A379163 A379164

Keyword

nonn

Author

Vincenzo Librandi, Dec 17 2024

Status

approved