Divisibility question

if n is an odd number that is divisible by 13, show that 2^n+1 is always divisible by 8193

can someone please explain this?!?

Did you notice 2^(13k) +1= (2^13)^k +1 is
divisible by (2^13+1) when k is odd?
This comes from (a+b) divides a^n + b^n for odd n.