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A042973
Primes p such that x^7 = 5 has no solution mod p.
2
29, 43, 113, 127, 197, 211, 239, 281, 337, 379, 421, 449, 463, 491, 547, 617, 631, 659, 673, 701, 743, 757, 911, 953, 967, 1009, 1051, 1093, 1163, 1289, 1373, 1429, 1471, 1499, 1583, 1597, 1667, 1709, 1723, 1877, 1933, 2003, 2017, 2087
OFFSET
1,1
COMMENTS
Complement of A216882 relative to A000040. - Vincenzo Librandi, Sep 19 2012
LINKS
MATHEMATICA
ok[p_]:= Reduce[Mod[x^7 - 5, p] == 0, x, Integers] == False; Select[Prime[Range[800]], ok] (* Vincenzo Librandi, Sep 19 2012 *)
PROG
(Magma) [p: p in PrimesUpTo(2500) | not exists{x : x in ResidueClassRing(p) | x^7 eq 5} ]; // Vincenzo Librandi, Sep 19 2012
CROSSREFS
Sequence in context: A039348 A043171 A043951 * A323628 A020997 A108280
KEYWORD
nonn,easy
STATUS
approved