A217356 Numbers n such that 8^n - 5 is prime.

1, 2, 4, 6, 12, 22, 50, 270, 606, 800, 1704, 5462, 6194, 9206, 10306, 105380

Offset: 1

Author

Vincenzo Librandi, Oct 02 2012

Keywords

• nonn

Comments

All terms are equal to 1/3 of the multiples of 3 in A059608.

Crossrefs

Cf. A059608, A217355.

Programs

Mathematica

Select[Range[4000], PrimeQ[8^# - 5] &]

PARI

is(n)=ispseudoprime(8^n-5) \\ Charles R Greathouse IV, Jun 06 2017