%I A117706
%S A117706 1,7,13,35,53,115,145,307,10163
%N A117706 Numbers n such that 6^n-n^6 is prime.
%C A117706 a(9) found by Donovan Johnson
%C A117706 Comment by Donovan Johnson : A117705 and A117706 are both Fermat probable 
               prime to four bases. They have also passed a Miller-Rabin primality 
               test in five randomly chosen bases. I checked the n values up to 
               70000 for A117705 and n values up to 60000 for A117706. No additional 
               primes or probable primes were found.
%e A117706 a(2)=7 because 6^7 - 7^6 = 162287 is prime
%t A117706 Do[If[PrimeQ[(6^n-n^6)],Print[n]],{n,1,3000}]
%Y A117706 Sequence in context: A060983 A001001 A067692 this_sequence A066673 A155036 
               A088985
%Y A117706 Adjacent sequences: A117703 A117704 A117705 this_sequence A117707 A117708 
               A117709
%K A117706 hard,more,nonn
%O A117706 1,2
%A A117706 Mohammed Bouayoun (Mohammed.Bouayoun(AT)sanef.com), Apr 13 2006, Jan 
               08 2008