1                    2   2.25000000    
           2                    4   2.44140625    
           3                    8   2.56578445    
           4                   16   2.63792849    
           5                   32   2.67698956    
           6                   64   2.69734550    
           7                  128   2.70773864    
           8                  256   2.71299291    
           9                  512   2.71563768    
          10                 1024   2.71695161    
          11                 2048   2.71761298    
          12                 4096   2.71795344    
          13                 8192   2.71812558    
          14                16384   2.71819711    
          15                32768   2.71823597    
          16                65536   2.71824193    
          17               131072   2.71814418    
          18               262144   2.71793771    
          19               524288   2.71663094    
          20              1048576   2.71339154    
          21              2097152   2.68823242    
          22              4194304   2.64062452    
          23              8388608   2.25000000    
          24             16777216   1.00000000    
          25             33554432   1.00000000    
          26             67108864   1.00000000    
          27            134217728   1.00000000    
          28            268435456   1.00000000    
          29            536870912   1.00000000    
          30           1073741824   1.00000000