A023263 Primes that remain prime through 2 iterations of function f(x) = 8x + 7.

2, 5, 107, 137, 179, 197, 227, 359, 419, 617, 659, 839, 977, 1097, 1217, 1409, 1487, 1559, 1637, 2087, 2339, 2447, 2549, 2609, 2687, 2909, 2957, 3167, 3299, 3467, 3719, 4139, 4409, 4787, 4919, 4937, 5147, 5189, 5279, 5639, 6047, 6269, 7229, 7547, 7949

Offset: 1

Author

David W. Wilson

Keywords

• nonn

Comments

Primes p such that 8*p+7 and 64*p+63 are also primes. - Vincenzo Librandi, Aug 04 2010

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Programs

Magma

[n: n in [1..100000] | IsPrime(n) and IsPrime(8*n+7)and IsPrime(64*n+63)]; // Vincenzo Librandi, Aug 04 2010

Mathematica

Select[Prime[Range[1100]],And@@PrimeQ[NestList[8#+7&,#,2]]&] (* Harvey P. Dale, Jul 22 2013 *)