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A062648
Numbers k such that 82^k - 81^k is prime.
0
2, 3, 13, 787, 797, 857, 1613, 37337
OFFSET
1,1
COMMENTS
Terms greater than 1000 are often only strong pseudoprimes.
a(9) > 10^5. - Robert Price, Jan 28 2015
MATHEMATICA
Select[Range[1000], PrimeQ[82^# - 81^#] &] (* Robert Price, Jan 28 2015 *)
PROG
(PARI) is(n)=ispseudoprime(82^n-81^n) \\ Charles R Greathouse IV, Jun 13 2017
KEYWORD
nonn,hard
AUTHOR
Mike Oakes, May 18 2001, May 19 2001
EXTENSIONS
a(8) from Robert Price, Jan 28 2015
STATUS
approved