7 stages, 2 taps:  (2 sets)

[7, 6]
[7, 4]


7 stages, 4 taps:  (5 sets)

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


7 stages, 6 taps:  (2 sets)

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