A359695 Numbers k such that 29^k - 2 is prime.

2, 4, 8, 14, 42, 420, 1344

Offset: 1

Author

Arsen Vardanyan, Mar 07 2023

Keywords

• nonn
• more

Comments

a(8) > 10^4, if it exists. - Amiram Eldar, Mar 10 2023

All terms in this sequence are even. - Yifan Xie, Mar 12 2023

a(8) > 5*10^4, if it exists. - Michael S. Branicky, Sep 14 2024

Examples

			4 is a term because 29^4 - 2 = 707279 is a prime number.
		

Crossrefs

Cf. A087886 (29^k + 2 is prime).

Cf. A128460, A128459, A128457, A109076, A090669, A105772, A109080, (and similar others).

Programs

Mathematica

Select[Range[1400], PrimeQ[29^# - 2] &] (* Amiram Eldar, Mar 10 2023 *)

PARI

is(k) = isprime(29^k - 2);