A023343 Primes that remain prime through 5 iterations of function f(x) = 5x + 6.

79, 34127, 345431, 549089, 669937, 703663, 948593, 978749, 999007, 1251329, 1255333, 1279133, 1500277, 1517413, 1525421, 1642769, 1670629, 1688101, 1727161, 1770127, 2152159, 2161343, 2328517, 2622167, 2745451, 2786681, 2837557, 3281777

Offset: 1

Author

David W. Wilson

Keywords

• nonn

Comments

Primes p such that 5*p+6, 25*p+36, 125*p+186, 625*p+936 and 3125*p+4686 are also primes. - Vincenzo Librandi, Aug 05 2010

Links

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

Crossrefs

Subsequence of A023219, A023254, A023285, A023315, and A081759.

Programs

Magma

[n: n in [1..10000000] | IsPrime(n) and IsPrime(5*n+6) and IsPrime(25*n+36) and IsPrime(125*n+186) and IsPrime(625*n+936) and IsPrime(3125*n+4686)] // Vincenzo Librandi, Aug 05 2010

Mathematica

Select[Prime[Range[250000]],And@@PrimeQ[Rest[NestList[5#+6&,#,5]]]&] (* Harvey P. Dale, Jan 03 2014 *)

Formula

a(n) == 9 (mod 14). - John Cerkan, Oct 20 2016