A038884 - OEIS

A038884

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

2, 5, 7, 11, 19, 31, 37, 41, 47, 59, 67, 71, 73, 83, 89, 97, 109, 137, 149, 151, 163, 167, 193, 197, 223, 227, 229, 239, 241, 271, 281, 293, 307, 317, 331, 349, 353, 359, 379, 383, 397, 401, 409, 421, 431, 449, 457

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Inert rational primes in the field Q(sqrt(13)). - N. J. A. Sloane, Dec 26 2017

Primes that are 5, 7, 11, 15, 19, 21 mod 26. - Charles R Greathouse IV, Mar 18 2018

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Index to sequences related to decomposition of primes in quadratic fields

FORMULA

a(n) ~ 2n log n. - Charles R Greathouse IV, Mar 18 2018

MATHEMATICA

Select[Prime@Range[120], JacobiSymbol[13, #] == -1 &] (* Vincenzo Librandi, Sep 08 2012 *)

PROG

(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

CROSSREFS

Sequence in context: A340759 A252280 A184774 * A338345 A252282 A337497

Adjacent sequences: A038881 A038882 A038883 * A038885 A038886 A038887

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

EXTENSIONS

Offset changed from 0 to 1 by Vincenzo Librandi, Sep 08 2012

STATUS

approved