A171058 Numbers k such that 3^k + 3*k + 1 is prime.

0, 1, 3, 41, 45, 83, 95, 181, 193, 195, 311, 325, 901, 1825, 3649, 7709, 16335, 45547

Offset: 1

Author

N. J. A. Sloane, Sep 04 2010, based on a posting to the Sequence Fans Mailing List by Charles R Greathouse IV, Aug 23 2010

Keywords

• nonn
• more

Comments

a(19) > 10^5. - Michael S. Branicky, Jul 25 2024

Crossrefs

Numbers k such that b^k + b*k + 1 is prime: A301634 (b=2), this sequence (b=3), A301635 (b=5).

Cf. A176805, A180269.

Programs

PARI

is(n)=ispseudoprime(3^n+3*n+1) \\ Charles R Greathouse IV, Jun 13 2017

Extensions

More terms from Charles R Greathouse IV, Sep 07 2010