A302988 Primes p such that p - 3 divides 3^p - 3.

2, 5, 7, 11, 13, 31, 73, 241, 367, 491, 577, 733, 757, 971, 991, 2593, 2731, 3307, 3391, 3529, 4591, 5113, 7591, 8011, 8713, 11131, 17377, 17911, 18433, 21757, 24181, 34651, 36559, 38921, 39367, 41141, 52951, 53593, 55201, 55681, 59051, 85933, 93871, 95791, 102241, 105031

Offset

1,1

Comments

Conjecture: the sequence is infinite.

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Mathematica

Select[Prime[Range[25]], Divisible[3^# - 3, # - 3] &] (* Alonso del Arte, Apr 17 2018 *)
Select[Range[10^5], # != 3 && PrimeQ[#] && PowerMod[3, #, # - 3] == Mod[3, # - 3] &] (* Amiram Eldar, Apr 06 2021 *)

Prog

(PARI) isok(p) = isprime(p) && (p != 3) && (Mod(3, p-3)^p == Mod(3, p-3)); \\ Michel Marcus, Apr 17 2018

Crossrefs

Cf. A000040, A000244, A302987.

Sequence in context: A079449 A236071 A038885 * A079379 A287004 A095272

Adjacent sequences: A302985 A302986 A302987 * A302989 A302990 A302991

Keyword

nonn

Author

Alex Ratushnyak, Apr 17 2018

Status

approved