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A038891 Odd primes p such that 19 is a square mod p. 3
3, 5, 17, 19, 31, 59, 61, 67, 71, 73, 79, 101, 103, 107, 127, 137, 149, 151, 157, 167, 179, 197, 211, 223, 227, 229, 233, 277, 307, 313, 331, 349, 353, 379, 383, 389, 397, 431, 439, 457, 461, 487, 523, 541, 547 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Also, only entries p=1 (mod 4) of the sequence are squares mod 19 (from the quadratic reciprocity law). - Lekraj Beedassy, Jul 21 2004

LINKS

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

MATHEMATICA

Select[Prime[Range[100]], JacobiSymbol[19, #] != -1 &] (* Vincenzo Librandi, Sep 07 2012 *)

PROG

(PARI) isok(p) = (p>2) && isprime(p) && issquare(Mod(19, p)); \\ Michel Marcus, Jun 23 2019

CROSSREFS

Sequence in context: A040129 A045415 A045416 * A287638 A119768 A020592

Adjacent sequences:  A038888 A038889 A038890 * A038892 A038893 A038894

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

EXTENSIONS

Name clarified by Michel Marcus, Jun 23 2019

STATUS

approved

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Last modified August 4 09:03 EDT 2020. Contains 336201 sequences. (Running on oeis4.)