login
A143833
Numbers n such that 14n^2 - 1 is prime.
4
1, 4, 5, 6, 10, 11, 16, 21, 26, 34, 36, 44, 45, 49, 54, 55, 59, 65, 69, 71, 76, 80, 85, 91, 95, 96, 100, 104, 106, 110, 114, 115, 120, 121, 125, 135, 139, 166, 169, 176, 180, 190, 195, 201, 204, 206, 214, 226, 230, 231, 234, 241, 254, 256, 264, 265, 269, 270, 275, 280
OFFSET
1,2
LINKS
MATHEMATICA
p = 14; a = {}; Do[k = p x^2 - 1; If[PrimeQ[k], AppendTo[a, x]], {x, 1, 1000}]; a
Select[Range[300], PrimeQ[14#^2-1]&] (* Harvey P. Dale, Aug 29 2011 *)
PROG
(PARI) is(n)=isprime(14*n^2-1) \\ Charles R Greathouse IV, Feb 20 2017
KEYWORD
nonn
AUTHOR
Artur Jasinski, Sep 02 2008
STATUS
approved