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Primes p such that 71 is not a square mod p.
1

%I #12 Sep 08 2022 08:44:53

%S 3,13,17,19,41,43,53,61,79,83,97,103,107,113,131,137,149,151,167,173,

%T 179,181,191,193,197,199,223,241,251,257,263,269,271,281,311,317,337,

%U 349,353,359,367,379,389,397,401

%N Primes p such that 71 is not a square mod p.

%C Also, only entries p=1 (mod 4) of the sequence are not squares mod 71 (from the quadratic reciprocity law). - _Lekraj Beedassy_, Jul 21 2004

%H Vincenzo Librandi, <a href="/A038956/b038956.txt">Table of n, a(n) for n = 1..1000</a>

%t Select[Prime@Range[120], JacobiSymbol[71, #] == - 1 &] (* _Vincenzo Librandi_, Sep 09 2012 *)

%o (Magma) [ p: p in PrimesUpTo(401) | not IsSquare(R! 71) where R:= ResidueClassRing(p) ]; // _Vincenzo Librandi_, Sep 10 2012

%K nonn,easy

%O 1,1

%A _N. J. A. Sloane_.

%E Offset changed from 0 to 1 by _Vincenzo Librandi_, Sep 09 2012