OFFSET
1,3
COMMENTS
a(21) > 20000. - Jinyuan Wang, Dec 14 2019
a(22) > 60000. - Michael S. Branicky, Jul 08 2024
MATHEMATICA
Do[ If[ PrimeQ[ 3*7^n + 2 ], Print[n] ], {n, 1, 6000} ]
PROG
(PARI) is(n)=ispseudoprime(3*7^n+2) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Robert G. Wilson v, Feb 12 2001
EXTENSIONS
a(19)-a(20) from Jinyuan Wang, Dec 14 2019
a(21) from Michael S. Branicky, Jul 07 2024
STATUS
approved