A215536 Numbers n such that 87^n - 86^n is prime.

2, 3, 47, 44563

Offset: 1

Author

Jean-Louis Charton, Aug 15 2012

Keywords

• nonn
• hard

Comments

a(5) > 10^5. - Robert Price, May 11 2015

Programs

Mathematica

Select[Prime[Range[PrimePi[1000]]], PrimeQ[87^# - 86^#] &] (* T. D. Noe, Aug 15 2012 *)

PARI

is(n)=ispseudoprime(87^n-86^n) \\ Charles R Greathouse IV, Jun 06 2017

Extensions

a(4) from Robert Price (computer run by Adam Marciniec), May 11 2015