A028880 Primes of the form n^2 - 6.

3, 19, 43, 163, 283, 523, 619, 2203, 2803, 3019, 4219, 4483, 5323, 5923, 6883, 7219, 9403, 11443, 12763, 13219, 15619, 17683, 20443, 21019, 24019, 27883, 34963, 37243, 38803, 41203, 42019, 46219, 55219, 69163, 75619, 85843, 100483

Offset

1,1

Comments

a(n) == 19 mod 24 for all n > 1. - Zak Seidov, Mar 10 2015

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

P. De Geest, Palindromic Quasipronics of the form n(n+x)

Formula

a(n) = A028879(n)^2 - 6. - Zak Seidov, Mar 10 2015

Mathematica

lst={}; Do[s=n^2; If[PrimeQ[p=s-6], AppendTo[lst, p]], {n, 7!}]; lst (* Vladimir Joseph Stephan Orlovsky, Sep 26 2008 *)

Prog

(Magma) [ a: n in [1..250] | IsPrime(a) where a is 4*n^2+4*n-5 ] // Vincenzo Librandi, Aug 05 2010
(PARI) for(n=1, 500, if(isprime(p=n^2-6), print1(p, ", "))) \\ Derek Orr, Mar 11 2014

Crossrefs

Sequence in context: A103145 A100694 A146664 * A162905 A201875 A063553

Adjacent sequences: A028877 A028878 A028879 * A028881 A028882 A028883

Keyword

nonn,easy

Author

Patrick De Geest

Status

approved