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A040975 Primes p such that x^5 = 15 has no solution mod p. 2

%I

%S 11,31,41,61,71,101,131,151,181,191,251,271,281,331,401,421,431,461,

%T 491,521,571,601,631,641,661,691,701,751,821,881,971,991,1021,1051,

%U 1061,1171,1181,1231,1291,1301,1321

%N Primes p such that x^5 = 15 has no solution mod p.

%C Complement of A040974 relative to A000040. - _Vincenzo Librandi_, Sep 18 2012

%H Vincenzo Librandi, <a href="/A040975/b040975.txt">Table of n, a(n) for n = 1..1000</a>

%t ok[p_]:= Reduce[Mod[x^5 - 15, p] == 0, x, Integers] == False; Select[Prime[Range[300]], ok] (* _Vincenzo Librandi_, Sep 18 2012 *)

%o (MAGMA) [p: p in PrimesUpTo(1500) | not exists{x : x in ResidueClassRing(p) | x^5 eq 15} ]; // _Vincenzo Librandi_, Sep 18 2012

%K nonn,easy

%O 1,1

%A _N. J. A. Sloane_.

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Last modified December 7 09:29 EST 2016. Contains 278849 sequences.