OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
MATHEMATICA
Select[Prime[Range[500]], !PrimeQ[20 # + 19] &]
(* Vincenzo Librandi, Feb 15 2014 *)
PROG
(Magma) [p: p in PrimesUpTo(400) | not IsPrime(20*p+19)]; // Vincenzo Librandi, Feb 15 2014
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Nov 04 2009
STATUS
approved