Is it possible to calculate the row position in the cartesian product of two arrays?

For example if you have one array of two rows and another of three rows it's easy to calculate the size of the cartesian product (Array1.Rows.Count * Array2.Rows.Count = 6), but you can't iterate through each array and just use the product of the respective row positions to calculate the row position in the cartesian product.

Array1.Row * Array2.Row
1 * 1 = 1
1 * 2 = 2
2 * 1 = 2
2 * 2 = 4
3 * 1 = 3
3 * 2 = 6

Is there a formula to obtain the result 1, 2, 3, 4, 5, 6 from Array1.Row and Array2.Row as you iterate through them in the following fashion:

For 1 To Array1.Rows.Count
    For 1 To Array2.Rows.Count
        'some formula here to get cartesian row position'
    Next Array2.Row
Next Array1.Row

Thanks!