The <em>correct answer</em> is:
1, 2, 3, 4, 5, 6, 10, 11, 12, 13, 14, 15, 16, 20, 21, 22, 23, 24, 25, 26.
Explanation:
The base 7 number system has digits 0 through 6.
When we start counting, we start with 1. In base 7, we would be able to go from 1 to 6, just as in base 10. However, in base 7, after we reach 6, we would hit 2 digits; instead of 7, the next number would be 10.
We would then count from 10 to 16. After we reach 16, instead of 17, we go to 20 and count from 20 to 26.
