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A062657
Numbers k such that 91^k - 90^k is prime.
0
2, 3, 101, 1117, 3109, 44959, 55259
OFFSET
1,1
COMMENTS
Terms greater than 1000 are often only strong pseudoprimes.
a(8) > 10^5. - Robert Price, Jul 21 2015
MATHEMATICA
Select[Range[0, 100000], PrimeQ[91^# - 90^#] &] (* Robert Price, Jul 21 2015 *)
PROG
(PARI) is(n)=ispseudoprime(91^n-90^n) \\ Charles R Greathouse IV, Jun 13 2017
KEYWORD
nonn,hard
AUTHOR
Mike Oakes, May 18 2001, May 19 2001
EXTENSIONS
a(6)-a(7) from Robert Price, Jul 21 2015
STATUS
approved