A217352 - OEIS

A217352

Numbers k such that 6^k - 7 is prime.

2, 4, 6, 8, 9, 10, 15, 20, 46, 49, 61, 98, 110, 144, 266, 344, 978, 1692, 1880, 1924, 3142, 3220, 4209, 5708, 7064, 13465, 13858, 19474, 22666

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

MATHEMATICA

Select[Range[10000], PrimeQ[6^# - 7] &]

PROG

(PARI) is(n)=ispseudoprime(6^n-7) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

KEYWORD

nonn,more,hard

AUTHOR

EXTENSIONS

a(26)-a(27) from Michael S. Branicky, Jan 29 2023

a(28)-a(29) from Michael S. Branicky, Apr 10 2023

STATUS

approved