Rule.

Start counting with 0.

1. Change to base 4, 
2. Change 2s to 3s and 3s to 2s
3. Change to base ten

0
1. Change 0 to base 4.  That's 04. 
2. Change 2s to 3s and 3s to 2s.  There are none. Still have 04.
3. Change to base ten.  That's 0.

1
1. Change 1 to base 4.  That's 14. 
2. Change 2s to 3s and 3s to 2s.  There are none. Still have 14
3. Change to base ten.  That's 1.

2
1. Change 2 to base 4.  That's 24. 
2. Change 2s to 3s and 3s to 2s.  Change 24 to 34. 
3. Change to base ten.  That's 3.

3
1. Change 3 to base 4.  That's 34. 
2. Change 2s to 3s and 3s to 2s.  Change 34 to 24
3. Change to base ten.  That's 2

4
1. Change 4 to base 4.  That's 104. 
2. Change 2s to 3s and 3s to 2s.  There are none. Still have 104
3. Change to base ten.  That's 4

5
1. Change 5 to base 4.  That's 114. 
2. Change 2s to 3s and 3s to 2s.  There are none. Still have 114
3. Change to base ten.  That's 5

6
1. Change 6 to base 4.  That's 124. 
2. Change 2s to 3s and 3s to 2s.  Change 124 to 134
3. Change to base ten.  That's 7

7
1. Change 7 to base 4.  That's 134. 
2. Change 2s to 3s and 3s to 2s.  Change 134 to 124
3. Change to base ten.  That's 6

8
1. Change 8 to base 4.  That's 204. 
2. Change 2s to 3s and 3s to 2s.  Change 204 to 304.
3. Change to base ten.  That's 12.

9
1. Change 9 to base 4.  That's 214. 
2. Change 2s to 3s and 3s to 2s.  Change 214 to 314.
3. Change to base ten.  That's 13.


1,3,2,4,5,7,6,12,13

Edwin