A216591 Numbers k such that 8^k + k^8 - 1 is prime.

10, 38, 428, 824, 3902, 4712, 5596, 29572

Offset: 1

Author

Vincenzo Librandi, Sep 09 2012

Keywords

• nonn
• hard
• more

Comments

a(9) > 10^5. Robert Price, Feb 25 2014

Crossrefs

Cf. A100357, A215434-A215446, A216375.

Programs

Mathematica

Select[Range[0, 4000],PrimeQ[8^# + #^8 - 1] &]

PARI

is(n)=ispseudoprime(8^n+n^8-1) \\ Charles R Greathouse IV, Jun 13 2017

Extensions

a(6)-a(8) from Robert Price, Feb 25 2014