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A224507
Numbers n such that (17^n + 2^n)/19 is prime.
2
5, 7, 113, 193, 211, 701, 797, 907, 4153
OFFSET
1,1
COMMENTS
All terms are prime.
a(10) > 10^5.
MATHEMATICA
Select[Prime[Range[1, 100000]], PrimeQ[(17^# + 2^#)/19]&]
PROG
(PARI) is(n)=ispseudoprime((17^n+2^n)/19) \\ Charles R Greathouse IV, Jun 06 2017
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Robert Price, Jul 20 2013
STATUS
approved