OFFSET
1,1
COMMENTS
Primes of the form 7x^2+3xy+9y^2, whose discriminant is -243. - T. D. Noe, May 17 2005
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
MATHEMATICA
ok[p_]:= Reduce[Mod[x^3 - 3, p] == 0, x, Integers] == False; Select[Prime[Range[200]], ok] (* Vincenzo Librandi, Sep 17 2012 *)
PROG
(Magma) [p: p in PrimesUpTo(1000) | not exists{x : x in ResidueClassRing(p) | x^3 eq 3} ]; // Vincenzo Librandi, Sep 17 2012
(PARI) forprime(p=2, 10^3, if(#polrootsmod(x^3-3, p)==0, print1(p, ", "))) \\ Joerg Arndt, Jul 16 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved