You should try doing this:
Count the smallest amount of tile on one side of the square.
There are eight, and 8X8=64 smallest tiles.
Next, the next to smallest amount of tiles have four smallest tiles, there are two smallest tiles on the side of a next to smallest tiles square. Because of that, there is (8/2=4) next to smallest tiles, and 4*4 = 16
And so on
4/2 = 2
2*2 =4
2/2 =1
1*1 =1
Then you add up all the squares of all the different size possible:
64+16+4+1 = 85 squares