My apologies. I misspoke.

Base 2 is the biunary numgbering system, having only two numbers, 0 and 1.

Base 3 would be the trinary system, which would have only 0, 1, and 2.

6 and 7 would be 110 and 111 respectively?

In binary, 6 = 110 and 7 = 111, yes.

There is no popular system called trinary but if there were, the decimal equivalents would be:

Dec Trinary
0 0
1 1
2 2
3 10
4 11
5 12
6 20
7 21


A