OFFSET
1,1
COMMENTS
All terms are primes.
No other terms < 100000.
MATHEMATICA
k=13; Select[ Prime[ Range[1, 200] ], PrimeQ[ ((k+3)^# - 3^#)/k ]& ]
PROG
(PARI) is(n)=isprime((16^n-3^n)/13) \\ Charles R Greathouse IV, Feb 17 2017
CROSSREFS
KEYWORD
hard,more,nonn
AUTHOR
Alexander Adamchuk, Feb 11 2007
EXTENSIONS
1747 from Farideh Firoozbakht, Apr 08 2007
a(6)=29683 from Robert Price, Sep 13 2011
STATUS
approved