A062652 Numbers k such that 86^k - 85^k is prime.

5, 11, 103, 227, 1637, 9677, 41597

Offset: 1

Author

Mike Oakes, May 18 2001, May 19 2001

Keywords

• nonn
• hard

Comments

Terms greater than 1000 are often only strong pseudoprimes.

All terms are prime. - Robert Price, Apr 14 2014

a(8) > 10^5. - Robert Price, Apr 14 2015

Crossrefs

Cf. A000043, A057468, A059801, A059802, A062572-A062666, A215536 (primes 87^n - 86^n).

Programs

Mathematica

Select[Range[0, 300], If[PrimeQ[#], PrimeQ[86^# - 85^#]] &] (* Robert Price, Apr 14 2015 *)

PARI

is(n)=ispseudoprime(86^n-85^n) \\ Charles R Greathouse IV, Jun 12 2017

Extensions

a(7) from Robert Price (computer run by Adam Marciniec), Apr 14 2015