OFFSET
1,2
COMMENTS
a(9) > 27376. - Jinyuan Wang, Dec 21 2019
a(9) > 60000. - Michael S. Branicky, Jul 10 2024
MATHEMATICA
Do[ If[ PrimeQ[ 2*7^n - 3 ], Print[n] ], {n, 1, 6000} ]
PROG
(PARI) is(n)=ispseudoprime(2*7^n-3) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Robert G. Wilson v, Feb 12 2001
EXTENSIONS
a(7)-a(8) from Jinyuan Wang, Dec 21 2019
STATUS
approved