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A040987
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Primes p such that x^5 = 21 has no solution mod p.
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2
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31, 41, 71, 101, 131, 151, 181, 191, 211, 241, 251, 271, 281, 311, 331, 401, 431, 491, 521, 541, 571, 701, 751, 761, 811, 821, 881, 911, 941, 971, 991, 1021, 1031, 1051, 1061, 1091, 1151, 1181, 1201, 1291, 1301, 1321, 1361, 1381, 1471
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OFFSET
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1,1
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COMMENTS
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LINKS
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MATHEMATICA
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ok[p_] := Reduce[Mod[x^5 - 21, p] == 0, x, Integers] == False; Select[Prime[Range[300]], ok] (* Vincenzo Librandi, Sep 19 2012 *)
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PROG
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(Magma) [p: p in PrimesUpTo(1500) | not exists{x: x in ResidueClassRing(p) | x^5 eq 21}]; // Vincenzo Librandi, Sep 19 2012
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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