login
A217320
Numbers n such that (13^n - 2^n)/11 is prime.
10
3, 5, 31, 73, 89, 521, 3943, 8719
OFFSET
1,1
COMMENTS
All terms are primes.
a(9) > 10^5.
MATHEMATICA
Select[ Prime[ Range[1, 100000] ], PrimeQ[ (13^# - 2^#)/11 ]& ]
PROG
(PARI) is(n)=ispseudoprime((13^n-2^n)/11) \\ Charles R Greathouse IV, Jun 06 2017
CROSSREFS
KEYWORD
hard,more,nonn
AUTHOR
Robert Price, Mar 18 2013
STATUS
approved