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

Author

Patrick De Geest

Keywords

• nonn
• easy

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)

Programs

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

Formula

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