OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..5000
MATHEMATICA
Select[Table[7n^2-1, {n, 1, 1000}], PrimeQ]
PROG
(Magma) [a: n in [1..400] | IsPrime(a) where a is 7*n^2-1];
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Dec 06 2011
STATUS
approved