A062617 Numbers k such that 51^k - 50^k is prime.

2, 7, 139, 383, 1187, 5857, 41281

Offset: 1

Author

Mike Oakes, May 18 2001, May 19 2001

Keywords

• nonn
• hard

Comments

Terms greater than 1000 are often only strong pseudoprimes.

a(8) > 10^5. - Robert Price, Feb 28 2013

Crossrefs

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

Programs

PARI

is(n)=ispseudoprime(51^n-50^n) \\ Charles R Greathouse IV, Jun 13 2017

Extensions

a(7) from Robert Price, Feb 28 2013