OFFSET
1,1
COMMENTS
From the Lifchitz link: 116240, 188858, and 230492 are also terms. - Michael S. Branicky, Jul 29 2024
LINKS
Henri Lifchitz and Renaud Lifchitz, PRP Records.
MATHEMATICA
lst={}; k=7; Do[If[PrimeQ[Abs[k^n-n^k]], AppendTo[lst, n]], {n, 0, 10^4}]; lst (* Vladimir Joseph Stephan Orlovsky, Sep 10 2008 *)
PROG
(PARI) is(n)=isprime(abs(7^n-n^7)) \\ Charles R Greathouse IV, Feb 17 2017
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Alexander Adamchuk, Mar 03 2007
EXTENSIONS
a(5) and a(6) from Donovan Johnson, Mar 03 2008
STATUS
approved