A062648 Numbers k such that 82^k - 81^k is prime.

2, 3, 13, 787, 797, 857, 1613, 37337

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(9) > 10^5. - Robert Price, Jan 28 2015

Crossrefs

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

Programs

Mathematica

Select[Range[1000], PrimeQ[82^# - 81^#] &] (* Robert Price, Jan 28 2015 *)

PARI

is(n)=ispseudoprime(82^n-81^n) \\ Charles R Greathouse IV, Jun 13 2017

Extensions

a(8) from Robert Price, Jan 28 2015