A038884 - OEIS

%I #15 May 24 2022 00:14:56

%S 2,5,7,11,19,31,37,41,47,59,67,71,73,83,89,97,109,137,149,151,163,167,

%T 193,197,223,227,229,239,241,271,281,293,307,317,331,349,353,359,379,

%U 383,397,401,409,421,431,449,457

%N Primes p such that 13 is not a square mod p.

%C Inert rational primes in the field Q(sqrt(13)). - _N. J. A. Sloane_, Dec 26 2017

%C Primes that are 5, 7, 11, 15, 19, 21 mod 26. - _Charles R Greathouse IV_, Mar 18 2018

%H Vincenzo Librandi, <a href="/A038884/b038884.txt">Table of n, a(n) for n = 1..1000</a>

%H <a href="https://oeis.org/index/Pri#primes_decomp_of">Index to sequences related to decomposition of primes in quadratic fields</a>

%F a(n) ~ 2n log n. - _Charles R Greathouse IV_, Mar 18 2018

%t Select[Prime@Range[120], JacobiSymbol[13, #] == -1 &] (* _Vincenzo Librandi_, Sep 08 2012 *)

%o (PARI) list(lim)=my(v=List()); foprime(p=2,lim, if(kronecker(13,p)<0, listput(v,p))); Vec(v) \\ _Charles R Greathouse IV_, Mar 18 2018

%K nonn,easy

%O 1,1

%A _N. J. A. Sloane_

%E Offset changed from 0 to 1 by _Vincenzo Librandi_, Sep 08 2012