A128448 Numbers k such that 8^k - k^8 is prime.

1, 11, 89, 201, 977, 1351, 3869, 60681

Offset: 1

Author

Alexander Adamchuk, Mar 03 2007

Keywords

• hard
• more
• nonn

Comments

From the Lifchitz link: 60681 and 85349 are also in this sequence. - Robert Price, Mar 27 2019

Links

• Henri Lifchitz and Renaud Lifchitz, PRP Records.

Crossrefs

Cf. A072180, A109387, A117705, A117706, A128447, A128449, A128450, A128451, A122003, A128453, A128454.

Programs

Mathematica

lst={};k=8;Do[If[PrimeQ[Abs[k^n-n^k]], AppendTo[lst, n]], {n, 0, 10^4}];lst (* Vladimir Joseph Stephan Orlovsky, Sep 10 2008 *)

PARI

is(n)=isprime(8^n-n^8) \\ Charles R Greathouse IV, Feb 17 2017

Extensions

a(6) and a(7) from Donovan Johnson, Feb 26 2008

a(8) confirmed (no intervening terms) by Michael S. Branicky, Jul 29 2024