OFFSET
1,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
MATHEMATICA
Select[Range[3100], Divisible[9^#+3^#, #]&] (* Harvey P. Dale, Aug 13 2015 *)
Select[Range[300], Divisible[PowerMod[9, #, #] + PowerMod[3, #, #], #] &] (* Amiram Eldar, Oct 23 2021 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved