1                    2   3.16235304    
           2                    4   3.14680052    
           3                    8   3.14289474    
           4                   16   3.14191818    
           5                   32   3.14167428    
           6                   64   3.14161301    
           7                  128   3.14159799    
           8                  256   3.14159393    
           9                  512   3.14159203    
          10                 1024   3.14159226    
          11                 2048   3.14159203    
          12                 4096   3.14159656    
          13                 8192   3.14159298    
          14                16384   3.14159203    
          15                32768   3.14159346    
          16                65536   3.14159107    
          17               131072   3.14158964    
          18               262144   3.14163303    
          19               524288   3.14144373    
          20              1048576   3.14189720    
          21              2097152   3.14097762    
          22              4194304   3.12674809    
          23              8388608   3.14532137    
          24             16777216   3.28064108    
          25             33554432   3.34059548    
          26             67108864   2.00000000    
          27            134217728   1.00000000    
          28            268435456  0.500000000    
          29            536870912  0.250000000    
          30           1073741824  0.125000000