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A090686 Primes of the form 6n^2 - 1. 13
5, 23, 53, 149, 293, 383, 599, 863, 1013, 1733, 2399, 2903, 4373, 4703, 5399, 6143, 7349, 8663, 11093, 12149, 16223, 18149, 20183, 21599, 23063, 23813, 25349, 27743, 29399, 31973, 33749, 35573, 40343, 41333, 45413, 51893, 56453, 59999, 62423 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Subset of A007528. The values of n for which 6*n^2 - 1 is prime are 1, 2, 3, 5, 7, 8, 10, 12, 13, 17, 20, 22, 27, 28, 30, 32, 35, 38, 43, 45, 52, 55, 58, 60, 62, 63, 65, 68, 70, 73, 75, 77, 82, 83, 87, 93, 97, 100, ... - Jonathan Vos Post, Aug 27 2006

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..5000

MATHEMATICA

lst={}; Do[p=6*n^2-1; If[PrimeQ[p], AppendTo[lst, p]], {n, 0, 3*5!}]; lst (* Vladimir Joseph Stephan Orlovsky, Jan 27 2009 *)

Select[Table[6n^2-1, {n, 0, 700}], PrimeQ] (* Vincenzo Librandi, Dec 05 2011 *)

PROG

(PARI) mx2pmp(n) = { for(x=1, n, y = 6*x^2-1; if(isprime(y), print1(y", ")) ) }

(MAGMA) [a: n in [0..500] | IsPrime(a) where a is 6*n^2-1]; // Vincenzo Librandi, Dec 05 2011

CROSSREFS

Cf. A000040, A007528, A090687.

Sequence in context: A140811 A247657 A241099 * A082277 A289154 A155851

Adjacent sequences:  A090683 A090684 A090685 * A090687 A090688 A090689

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

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Last modified December 14 12:04 EST 2019. Contains 329979 sequences. (Running on oeis4.)