%I #3 Mar 30 2012 17:30:27
%S 1,5,25,125,625,925,3125,5675,15625,15845,70625,78125,390625,1223375,
%T 1953125,4328125,5328475,9765625
%N Numbers n such that n | 9^n + 7^n + 5^n + 3^n +1.
%t Select[ Range[ 10^7 ], Mod[ PowerMod[ 9, #, # ] + PowerMod[ 7, #, # ] + PowerMod[ 5, #, # ] + PowerMod[ 3, #, # ] + 1, # ] == 0 & ]
%K nonn
%O 1,2
%A _Robert G. Wilson v_, Nov 08 2000