OFFSET
1,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
MATHEMATICA
Select[Range[350], PrimeQ[7 # - 4] &] (* Vincenzo Librandi, Sep 26 2012 *)
PROG
(Magma) [n: n in [1..400] | IsPrime(7*n-4)]; // Vincenzo Librandi, Nov 20 2010
(PARI) is(n)=isprime(7*n-4) \\ Charles R Greathouse IV, Feb 17 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved