OFFSET
1,1
COMMENTS
Terms greater than 1000 are often only strong pseudoprimes.
a(5) > 10^5. - Robert Price, Dec 16 2013
PROG
(PARI) is(n)=ispseudoprime(69^n-68^n) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
KEYWORD
nonn,hard,bref
AUTHOR
Mike Oakes, May 18 2001, May 19 2001
EXTENSIONS
a(4) from Robert Price, Dec 16 2013 (Computer run by Adam Marciniec)
STATUS
approved