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A213176
Numbers n such that (13^n + 4^n)/17 is prime.
2
7, 11, 31, 59, 73, 137, 563, 34819, 48751, 73849
OFFSET
1,1
COMMENTS
All terms are prime.
a(11) > 10^5.
MATHEMATICA
Select[ Prime[ Range[1, 100000] ], PrimeQ[ (13^# + 4^#)/17 ]& ]
PROG
(PARI) is(n)=ispseudoprime((13^n+4^n)/17) \\ Charles R Greathouse IV, Jun 06 2017
CROSSREFS
KEYWORD
hard,nonn,more
AUTHOR
Robert Price, May 03 2013
STATUS
approved