A364078 Numbers k such that (18^k - 1)^2 - 2 is prime.

2, 8, 30, 98, 110, 185, 912, 2514, 4074, 10208, 15123, 19395, 69354

Offset

1,1

Comments

Such primes are sometimes called Carol primes of base 18.

Links

Table of n, a(n) for n=1..13.

Prime-Wiki, Carol-Kynea prime.

Eric Weisstein's World of Mathematics, Near-Square Prime.

Prog

(PARI) for(k=1, 1200, ispseudoprime((18^k-1)^2-2)&&print1(k, ", "))

Crossrefs

Cf. A091515 (b=2), A100901 (b=6), A100903 (b=10), A364076 (b=12), A100905 (b=14), A364080 (b=20), A100907 (b=22).

Cf. A364079.

Sequence in context: A131318 A010749 A299415 * A230701 A365693 A168605

Adjacent sequences: A364075 A364076 A364077 * A364079 A364080 A364081

Keyword

nonn,hard,more

Author

Jeppe Stig Nielsen, Jul 03 2023

Status

approved