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A040984
Primes p such that x^23 = 2 has no solution mod p.
16
47, 139, 277, 461, 599, 691, 829, 967, 1013, 1151, 1289, 1381, 1427, 1657, 1933, 1979, 2347, 2393, 2531, 3037, 3083, 3221, 3313, 3359, 3727, 3911, 4003, 4049, 4463, 4831, 4877, 4969, 5107, 5521, 5659, 5843, 5981, 6073, 6211, 6257, 6763, 6947, 7039, 7177
OFFSET
1,1
COMMENTS
Contribution from Charles R Greathouse IV, Sep 12 2012: (Start)
Complement of A049555 relative to A000040.
Terms of A212374 which are not in this sequence: 5153, 18539, 20747, 49681, 51199, 51797, 55201, 70381, .... (End)
LINKS
MATHEMATICA
Select[Prime[Range[PrimePi[7200]]], ! MemberQ[PowerMod[Range[#], 23, #], Mod[2, #]] &] (* T. D. Noe, Sep 13 2012 *)
ok[p_]:=Reduce[Mod[x^23 - 2, p]==0, x, Integers]==False; Select[Prime[Range[25000]], ok] (* Vincenzo Librandi, Sep 13 2012 *)
PROG
(Magma) [p: p in PrimesUpTo(8000) | forall{x: x in ResidueClassRing(p) | x^23 ne 2}]; // Vincenzo Librandi, Aug 21 2012
(PARI) select(n->!ispower(Mod(2, n), 23), primes(1000)) \\ Charles R Greathouse IV, Sep 12 2012
CROSSREFS
Cf. A212374.
Sequence in context: A355727 A062637 A212374 * A136070 A374274 A055822
KEYWORD
nonn,easy
AUTHOR
Klaus Brockhaus, Jan 20 2001
STATUS
approved