A062636 Numbers k such that 70^k - 69^k is prime.

2, 11, 1301, 78989, 83117

Offset: 1

Author

Mike Oakes, May 18 2001, May 19 2001

Keywords

• nonn
• hard
• bref

Comments

Terms greater than 1000 are often only strong pseudoprimes.

a(6) > 10^5. - Robert Price Jan 15 2014

Crossrefs

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

Programs

PARI

is(n)=ispseudoprime(70^n-69^n) \\ Charles R Greathouse IV, Jun 13 2017

Extensions

a(4)-a(5) from Robert Price, Jan 15 2014 (Computer run by Adam Marciniec)