A062635 Numbers k such that 69^k - 68^k is prime.

2, 17, 1543, 83653

Offset

1,1

Comments

Terms greater than 1000 are often only strong pseudoprimes.

a(5) > 10^5. - Robert Price, Dec 16 2013

Links

Table of n, a(n) for n=1..4.

Prog

(PARI) is(n)=ispseudoprime(69^n-68^n) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Cf. A000043, A057468, A059801, A059802, A062572-A062666.

Sequence in context: A261535 A327020 A058233 * A060835 A122054 A284706

Adjacent sequences: A062632 A062633 A062634 * A062636 A062637 A062638

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