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A359695
Numbers k such that 29^k - 2 is prime.
0
2, 4, 8, 14, 42, 420, 1344
OFFSET
1,1
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
EXAMPLE
4 is a term because 29^4 - 2 = 707279 is a prime number.
MATHEMATICA
Select[Range[1400], PrimeQ[29^# - 2] &] (* Amiram Eldar, Mar 10 2023 *)
PROG
(PARI) is(k) = isprime(29^k - 2);
CROSSREFS
Cf. A087886 (29^k + 2 is prime).
Cf. A128460, A128459, A128457, A109076, A090669, A105772, A109080, (and similar others).
Sequence in context: A355189 A093483 A028398 * A155249 A118884 A118890
KEYWORD
nonn,more
AUTHOR
Arsen Vardanyan, Mar 07 2023
STATUS
approved