OFFSET
1,1
COMMENTS
All terms are primes.
No other terms exist < 100000.
MATHEMATICA
k=10; Select[ Prime[ Range[1, 200] ], PrimeQ[ ((k+3)^# - 3^#)/k ]& ]
PROG
(PARI) is(n)=isprime((13^n-3^n)/10) \\ Charles R Greathouse IV, Feb 17 2017
CROSSREFS
KEYWORD
hard,more,nonn
AUTHOR
Alexander Adamchuk, Feb 11 2007
EXTENSIONS
One more term from Farideh Firoozbakht, Apr 03 2007
a(7)=8803 from Robert Price, Aug 12 2011
STATUS
approved