8 stages, 4 taps:  (6 sets)

[8, 7, 6, 1]
[8, 7, 5, 3]
[8, 7, 3, 2]
[8, 6, 5, 4]
[8, 6, 5, 3]
[8, 6, 5, 2]


8 stages, 6 taps:  (2 sets)

[8, 7, 6, 5, 4, 2]
[8, 7, 6, 5, 2, 1]