A059331 - OEIS

A059331

Primes p such that x^24 = 2 has no solution mod p, but x^12 = 2 has a solution mod p.

113, 281, 353, 593, 617, 1049, 1097, 1193, 1481, 1601, 1753, 1889, 2129, 2273, 2281, 2393, 2689, 3089, 3137, 3761, 3833, 4001, 4153, 4217, 4289, 4457, 4657, 4817, 4937, 5113, 5393, 5569, 6521, 6569, 6761, 7481, 7577, 7793, 7817, 7841, 8273, 8369, 8537

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OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..370

MATHEMATICA

Select[Prime[Range[PrimePi[1000]]], !MemberQ[PowerMod[Range[#], 24, #], Mod[2, #]] && MemberQ[PowerMod[Range[#], 12, #], Mod[2, #]]&] (* Vincenzo Librandi, Sep 21 2013 *)

PROG

(Magma) [p: p in PrimesUpTo(9000) | not exists{x: x in ResidueClassRing(p) | x^24 eq 2} and exists{x: x in ResidueClassRing(p) | x^12 eq 2}]; // Vincenzo Librandi, Sep 21 2012

CROSSREFS

A000040, A049556, A049544, A059264.

Sequence in context: A070181 A001134 A070188 * A124586 A051110 A031932

Adjacent sequences: A059328 A059329 A059330 * A059332 A059333 A059334

KEYWORD

nonn,easy

AUTHOR

Klaus Brockhaus, Jan 26 2001

STATUS

approved