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A059310
Primes p such that x^21 = 2 has no solution mod p.
2
7, 13, 19, 29, 37, 43, 61, 67, 71, 73, 79, 97, 103, 113, 127, 139, 151, 163, 181, 193, 197, 199, 211, 239, 241, 271, 281, 313, 331, 337, 349, 367, 373, 379, 409, 421, 449, 463, 487, 491, 523, 541, 547, 571, 577, 607, 613, 617, 619, 631, 659, 661, 673, 701
OFFSET
1,1
COMMENTS
Complement of A049553 relative to A000040.
LINKS
MATHEMATICA
ok[p_] := Reduce[Mod[x^21 - 2, p] == 0, x, Integers] == False; Select[Prime[Range[150]], ok] (* Vincenzo Librandi, Sep 20 2012 *)
PROG
(Magma) [p: p in PrimesUpTo(710) | not exists{x: x in ResidueClassRing(p) | x^21 eq 2}]; // Vincenzo Librandi, Sep 20 2012
CROSSREFS
Sequence in context: A096452 A258038 A059647 * A299929 A287217 A101324
KEYWORD
nonn,easy
AUTHOR
Klaus Brockhaus, Jan 25 2001
STATUS
approved