OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
MATHEMATICA
ok[p_]:=Reduce[Mod[x^42 + 2, p] == 0, x, Integers] == False; Select[Prime[Range[300]], ok] (* Vincenzo Librandi, Sep 16 2012 *)
PROG
(Magma) [p: p in PrimesUpTo(500) | not exists{x : x in ResidueClassRing(p) | x^42 eq -2} ];
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Sep 16 2012
STATUS
approved