A023297 Primes that remain prime through 3 iterations of function f(x) = 9x + 4.

3, 31, 37, 41, 107, 421, 773, 967, 1451, 1567, 1571, 1637, 1973, 3011, 3793, 4111, 4217, 4703, 5783, 6961, 7331, 8443, 8627, 9323, 10733, 12071, 12413, 12721, 12967, 13523, 14107, 14503, 14737, 15647, 17851, 17881, 19853, 19991, 20051, 20233, 22157, 23291

Offset: 1

Author

David W. Wilson

Keywords

• nonn

Comments

Primes p such that 9*p+4, 81*p+40 and 729*p+364 are also primes. - Vincenzo Librandi, Aug 04 2010

Links

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

Crossrefs

Subsequence of A023234 and A023266.

Programs

Magma

[n: n in [1..450000] | IsPrime(n) and IsPrime(9*n+4) and IsPrime(81*n+40) and IsPrime(729*n+364)]; // Vincenzo Librandi, Aug 04 2010