Combining Cuisenaire


2 different rods: 2
2 the same: 1

3 different rods: 6
3 rods with 2 the same: 3
3 the same: 1

4 different rods: 24
4 rods with 2 the same: 12
4 rods with 3 the same:4
4 rods the same: 1