A023325 Primes that remain prime through 4 iterations of function f(x) = 9x + 4.

3, 107, 421, 773, 1567, 1637, 3793, 4111, 6961, 12721, 14107, 17851, 26267, 26557, 31327, 33503, 37003, 42281, 57947, 60091, 65423, 67427, 68447, 75721, 82223, 82657, 87877, 96377, 108107, 111373, 113171, 122117, 123887, 125497, 125887, 127301

Offset: 1

Author

David W. Wilson

Keywords

• nonn

Comments

Primes p such that 9*p+4, 81*p+40, 729*p+364 and 6561*p+3280 are also primes. - Vincenzo Librandi, Aug 04 2010

Links

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

Crossrefs

Subsequence of A023234, A023266, and A023297.

Programs

Magma

[n: n in [1..5000000] | IsPrime(n) and IsPrime(9*n+4) and IsPrime(81*n+40) and IsPrime(729*n+364) and IsPrime(6561*n+3280)] // Vincenzo Librandi, Aug 04 2010