Ternary Expansions and Cantor Set

The problem is to find out for what values of p (for integers between 0 and 13), is p/13 in the cantor set. I know that they are only in the cantor set if they can be expressed in the ternary expansion to base 3 using only 2's and 0's. I have a lot of problems with these ternary expansions so I was wondering if you guys could check my work quick, and let me know where I have gone wrong.

THANKS

1/13=

2/13=2x1/13=(.004004...)=

3/13=3x1=

4/13=2x2/13=

5/13=4/13+1/13=

6/13=3x2/13=

7/13=6/13+1/13=

8/13=7/13+1/13=

9/13=3x3/13=

10/13=9/13+1/13=

11/13=2/13+9/13=

12/13=3x4/13=