A023346 Primes that remain prime through 5 iterations of function f(x) = 7x + 6.

4259, 174079, 253369, 275699, 448859, 527159, 539639, 649969, 1101509, 1218559, 1230629, 1319729, 1426889, 1780939, 1929899, 1947109, 1960919, 2082469, 2087419, 2262409, 2479619, 2499169, 2797999, 2808359, 2809439, 2813339, 3089059, 3363749

Offset: 1

Author

David W. Wilson

Keywords

• nonn

Comments

Primes p such that 7*p+6, 49*p+48, 343*p+342, 2401*p+2400 and 16807*p+16806 are also primes. - Vincenzo Librandi, Aug 05 2010

Links

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

Crossrefs

Subsequence of A023225, A023259, A023290, A023318, and A024900.

Programs

Magma

[n: n in [1..10000000] | IsPrime(n) and IsPrime(7*n+6) and IsPrime(49*n+48) and IsPrime(343*n+342) and IsPrime(2401*n+2400) and IsPrime(16807*n+16806)] // Vincenzo Librandi, Aug 05 2010

Formula

a(n) == 9 (mod 10). - John Cerkan, Oct 24 2016