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A229542
Numbers n such that (19^n - 2^n)/17 is prime.
3
11, 19, 79, 631, 1787, 2011, 2381, 20219, 49523
OFFSET
1,1
COMMENTS
All terms are primes.
a(10) > 2*10^5.
MATHEMATICA
Select[ Prime[ Range[1, 100000] ], PrimeQ[ (19^# - 2^#)/17 ]& ]
PROG
(PARI) is(n)=ispseudoprime((19^n-2^n)/17) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Robert Price, Sep 25 2013
STATUS
approved