OFFSET
1,1
MATHEMATICA
Select[ Range[219], !PrimeQ[2# + 1] && PrimeQ[2# - 1] &] (* Robert G. Wilson v, Apr 18 2005 *)
PROG
(Magma) [n: n in [0..250]| not IsPrime(2*n+1) and IsPrime(2*n-1)] // Vincenzo Librandi, Jan 28 2011
(PARI) is(n)=isprime(2*n-1) && !isprime(2*n+1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Alexandre Wajnberg, Apr 17 2005
EXTENSIONS
More terms from Robert G. Wilson v, Apr 18 2005
STATUS
approved