OFFSET
1,1
COMMENTS
All terms are prime.
a(7) > 10^5.
MATHEMATICA
Select[ Prime[ Range[1, 100000] ], PrimeQ[ (11^# + 4^#)/15 ]& ]
PROG
(PARI) is(n)=ispseudoprime((11^n+4^n)/15) \\ Charles R Greathouse IV, Jun 06 2017
CROSSREFS
KEYWORD
hard,nonn,more
AUTHOR
Robert Price, Apr 08 2013
STATUS
approved