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A090687
Primes of the form 6*k^2 + 1.
4
7, 97, 151, 487, 601, 727, 2647, 3457, 4057, 7351, 9127, 9601, 11617, 12697, 14407, 15607, 17497, 20887, 21601, 29401, 33751, 37447, 39367, 42337, 47527, 53017, 54151, 71287, 77977, 80737, 84967, 95257, 102967, 110977, 126151, 142297, 151687
OFFSET
1,1
COMMENTS
Subset of A002476. See also A121326. The values of k for which 6*k^2 + 1 is prime are 1, 4, 5, 9, 10, 11, 21, 24, 26, 35, 39, 40, 44, 46, 49, 51, 54, 59, 60, 70, 75, 79, 81, 84, 89, 94, 95, 109, 114, 116, 119, 126, 131, 136, 145, 154, ... - Jonathan Vos Post, Aug 27 2006
LINKS
MATHEMATICA
Select[Table[6n^2+1, {n, 0, 1000}], PrimeQ] (* Vincenzo Librandi, Dec 03 2011 *)
PROG
(PARI) mx2pmp(n) = { for(x=1, n, y = 6*x^2+1; if(isprime(y), print1(y", ")) ) }
(Magma) [a: n in [0..600] | IsPrime(a) where a is 6*n^2+1]; // Vincenzo Librandi, Dec 03 2011
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Cino Hilliard, Dec 18 2003
EXTENSIONS
Edited by N. J. A. Sloane at the suggestion of R. J. Mathar, Apr 14 2008
STATUS
approved