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A040148
Primes p such that x^4 = 20 has no solution mod p.
2
3, 7, 13, 17, 23, 37, 41, 43, 47, 53, 67, 73, 83, 89, 97, 101, 103, 107, 109, 113, 127, 137, 149, 157, 163, 167, 173, 181, 193, 197, 223, 227, 233, 241, 257, 263, 269, 277, 281, 283, 293, 307, 313, 317, 337, 347
OFFSET
1,1
COMMENTS
Complement of A040147 relative to A000040. - Vincenzo Librandi, Sep 18 2012
LINKS
MATHEMATICA
ok[p_]:= Reduce[Mod[x^4 - 20, p] == 0, x, Integers] == False; Select[Prime[Range[100]], ok] (* Vincenzo Librandi, Sep 18 2012 *)
PROG
(Magma) [p: p in PrimesUpTo(500) | not exists{x : x in ResidueClassRing(p) | x^4 eq 20} ]; // Vincenzo Librandi, Sep 18 2012
CROSSREFS
Sequence in context: A191028 A034914 A034913 * A097957 A071774 A019403
KEYWORD
nonn,easy
AUTHOR
STATUS
approved