1, 2, 3, 4, 5
   differences 1, 1, 1, 1 # constant
1, 2, 4, 8, 16
   ratios:     2, 2, 2, 2 # constant
1, 2, 3, 5, 8
   differences: 1, 2, 3, 5 # sames as original  shifted by one
1, 11, 111, 1111, 11111
   differences: 10, 100, 1000, 10000
       ratios: 10, 10, 10 # constant