A058025 Numbers k such that 3*13^k - 2 is prime.

1, 5, 11, 16, 59, 239, 299, 2524, 2695, 7657, 14028, 24104

Offset

1,2

Comments

The next terms are > 15000. - Jinyuan Wang, Feb 02 2020

Links

Table of n, a(n) for n=1..12.

Example

3(13^5) - 2 = 1113877, which is a prime number, hence 5 is in the sequence.
3(13^7) - 2 = 188245549, but that is divisible by 211, hence 7 is NOT a term.

Mathematica

Do[ If[ PrimeQ[ 3*13^n - 2 ], Print[ n ] ], {n, 0, 1500} ] (* RGWv *)
Select[Range[0, 4000], PrimeQ[(3*13^# - 2)] &] (* Vincenzo Librandi, Sep 28 2012 *)

Prog

(PARI) is(n)=ispseudoprime(3*13^n-2) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Cf. A057871 (3*13^k + 2 is prime).

Sequence in context: A041046 A041117 A041491 * A042121 A123082 A084037

Adjacent sequences: A058022 A058023 A058024 * A058026 A058027 A058028

Keyword

nonn,more

Author

Robert G. Wilson v, Nov 15 2000

Extensions

a(8)-a(9) from Vincenzo Librandi, Sep 28 2012

a(10) from Bruno Berselli, Sep 28 2012

a(11) from Jinyuan Wang, Feb 02 2020

a(12) from Michael S. Branicky, Jun 29 2023

Status

approved