Why doe the sequence 16*[10,6,5,9] work for a bipolar stepper motor?
10  1 0 1 0
6   0 1 1 0
5   0 1 0 1
9   1 0 0 1


if you motor is wireed A+ A- B+ B-  that will drive it perfectly
or to put it another way, swap the middle two columns and you'll see the staircase pattern

    1 1 0 0
    0 1 1 0
    0 0 1 1
    1 0 0 1