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
KEYWORD
nonn
AUTHOR
EXTENSIONS
Name clarified by Michel Marcus, Jun 23 2019
STATUS
approved