OFFSET
1,1
COMMENTS
Three larger terms 18494, 23840 and 36838 found by Donovan Johnson, Jul-Aug 2005.
From the Lifchitz link: 83024 is also a term. - Michael S. Branicky, Jul 29 2024
LINKS
Henri Lifchitz and Renaud Lifchitz, PRP Records.
MATHEMATICA
lst={}; k=9; 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(9^n-n^9)) \\ Charles R Greathouse IV, Feb 17 2017
CROSSREFS
KEYWORD
hard,more,nonn
AUTHOR
Alexander Adamchuk, Mar 03 2007
EXTENSIONS
a(4)-a(6) from Ryan Propper, Feb 22 2008
a(7) from Donovan Johnson, Feb 26 2008
STATUS
approved