A038928 - OEIS

A038928

Primes p such that 47 is not a square mod p.

3, 5, 7, 13, 29, 41, 59, 71, 73, 79, 83, 103, 109, 113, 131, 137, 181, 191, 193, 229, 233, 239, 251, 257, 263, 271, 281, 283, 293, 307, 313, 317, 331, 347, 349, 373, 379, 383, 389, 409, 421, 431, 433, 439, 449

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OFFSET

1,1

COMMENTS

Also, only entries p=1 (mod 4) of the sequence are not squares mod 47 (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[120], JacobiSymbol[47, #] == -1 &] (* Vincenzo Librandi, Sep 09 2012 *)

PROG

(PARI) select(n->!issquare(Mod(47, n)), primes(100)) \\ Charles R Greathouse IV, Sep 09 2012

CROSSREFS

Sequence in context: A224221 A128547 A087383 * A359436 A225504 A089740

Adjacent sequences: A038925 A038926 A038927 * A038929 A038930 A038931

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

EXTENSIONS

Offset changed from 0 to 1 by Vincenzo Librandi, Sep 09 2012

STATUS

approved