A023318 Primes that remain prime through 4 iterations of function f(x) = 7x + 6.

1319, 2699, 4259, 4919, 5689, 8669, 10159, 10529, 29819, 33119, 82339, 86689, 98669, 174079, 177949, 196739, 207869, 210599, 222499, 231809, 253369, 267299, 275699, 323699, 362459, 371639, 378179, 388529, 397799, 402529, 421079, 448859, 468499

Offset: 1

Author

David W. Wilson

Keywords

• nonn

Comments

Primes p such that 7*p+6, 49*p+48, 343*p+342 and 2401*p+2400 are also primes. - Vincenzo Librandi, Aug 04 2010

Links

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

Crossrefs

Subsequence of A023225, A023259, A023290, and A024900.

Programs

Magma

[n: n in [1..1000000] | IsPrime(n) and IsPrime(7*n+6) and IsPrime(49*n+48) and IsPrime(343*n+342) and IsPrime(2401*n+2400)] // Vincenzo Librandi, Aug 04 2010

Formula

a(n) == 9 (mod 10). - John Cerkan, Oct 08 2016