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A062608
Numbers k such that 42^k - 41^k is prime.
1
2, 3, 5, 47, 67, 103
OFFSET
1,1
COMMENTS
Terms greater than 1000 are often only strong pseudoprimes.
No further terms up to 5000. - Harvey P. Dale, Mar 13 2011
a(7) > 10^5. - Robert Price, Sep 21 2012
MATHEMATICA
Select[Range[5000], PrimeQ[42^# - 41^#] &] (* Harvey P. Dale, Mar 13 2011 *)
PROG
(PARI) is(n)=ispseudoprime(42^n-41^n) \\ Charles R Greathouse IV, Jun 12 2017
KEYWORD
nonn,hard,more
AUTHOR
Mike Oakes, May 18 2001, May 19 2001
STATUS
approved