T(n) = 4T(n/2) + n,  T(1) = 1
n         T(n)            2n^3            2n^2 - n            T(n)/n^2
--------------------------------------------------------------------------
1         1               2               1                   1.0000
2         6               16              6                   1.5000
4         28              128             28                  1.7500
8         120             1024            120                 1.8750
16        496             8192            496                 1.9375
32        2016            65536           2016                1.9688
64        8128            524288          8128                1.9844
128       32640           4194304         32640               1.9922
256       130816          33554432        130816              1.9961
512       523776          268435456       523776              1.9980
1024      2096128         2147483648      2096128             1.9990

T(n) = 2T(n/2) + n,  T(1) = 1   (Merge Sort)
n         T(n)            n lg n + n          T(n)/(n lg n)
------------------------------------------------------------------
2         4               4                   2.0000
4         12              12                  1.5000
8         32              32                  1.3333
16        80              80                  1.2500
32        192             192                 1.2000
64        448             448                 1.1667
128       1024            1024                1.1429
256       2304            2304                1.1250
512       5120            5120                1.1111
1024      11264           11264               1.1000
