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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 (list; graph; refs; listen; history; text; internal format)
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

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

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. A000040, A049555.

Cf. A212374.

Sequence in context: A005112 A062637 A212374 * A136070 A055822 A044379

Adjacent sequences:  A040981 A040982 A040983 * A040985 A040986 A040987

KEYWORD

nonn,easy

AUTHOR

Klaus Brockhaus, Jan 20 2001

STATUS

approved

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Last modified August 6 22:03 EDT 2020. Contains 336256 sequences. (Running on oeis4.)