A023294 Primes that remain prime through 3 iterations of function f(x) = 8x + 7.

659, 2549, 5189, 6269, 7229, 7949, 9209, 11579, 16139, 18089, 22739, 25589, 26099, 26339, 29009, 30689, 40289, 51719, 55799, 59669, 60689, 61379, 63599, 69959, 70229, 74609, 85829, 94949, 95819, 102539, 109589, 118169, 121469, 135599, 136889

Offset: 1

Author

David W. Wilson

Keywords

• nonn

Comments

Primes p such that 8*p+7, 64*p+63 and 512*p+511 are also primes. - Vincenzo Librandi, Aug 04 2010

Links

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

Crossrefs

Subsequence of A023231, A023263, and A139487.

Programs

Magma

[n: n in [1..450000] | IsPrime(n) and IsPrime(8*n+7) and IsPrime(64*n+63) and IsPrime(512*n+511)]; // Vincenzo Librandi, Aug 04 2010

Formula

a(n) == 29 (mod 30). - John Cerkan, Sep 23 2016