A023315 Primes that remain prime through 4 iterations of function f(x) = 5*x + 6.

79, 401, 1259, 2477, 3019, 4409, 10303, 15679, 20509, 24499, 34127, 43987, 44389, 53101, 66359, 71287, 74857, 81097, 85903, 90803, 93053, 102811, 103231, 104999, 112601, 125453, 132533, 144731, 156347, 157793, 160817, 161839, 163981, 170641

Offset: 1

Author

David W. Wilson

Keywords

• nonn

Comments

Primes p such that 5*p+6, 25*p+36, 125*p+186 and 625*p+936 are also primes. - Vincenzo Librandi, Aug 04 2010

Links

• John Cerkan, Table of n, a(n) for n = 1..10000

Crossrefs

Subsequence of A023219, A023254, A023285, and A081759.

Programs

Magma

[n: n in [1..1000000] | IsPrime(n) and IsPrime(5*n+6) and IsPrime(25*n+36) and IsPrime(125*n+186) and IsPrime(625*n+936)]; // Vincenzo Librandi, Aug 04 2010

Formula

a(n) == 9 or 13 (mod 14). - John Cerkan, Oct 07 2016