y       x
            1.00000    0
            1.11111    1
            1.24992    2
            1.42753    3
            1.65984    4
            1.96875    5
            2.38336    6
            2.94117    7
            3.68928    8
            4.68559    9
            6.00000   10
            7.71561   11
            9.92992   12
           12.75603   13
           16.32384   14
           20.78125   15
           26.29536   16
           33.05367   17
           41.26528   18
           51.16209   19
           63.00000   20