m=400 r=50
small: odd b < 2^11 (n=1024):
   x:                1         2         3         4         6         8        10
   mean tail  9.77e-03  1.21e-04  5.84e-10  7.88e-25  0.00e+00  0.00e+00  0.00e+00
   max tail   5.42e-01  7.03e-02  5.50e-07  7.83e-22  0.00e+00  0.00e+00  0.00e+00
   argmax b       1603      1603       433       233         1         1         1
random odd b < 2^(m-3) (n=300):
   x:                1         2         3         4         6         8        10
   mean tail  2.09e-02  2.40e-03  9.79e-06  0.00e+00  0.00e+00  0.00e+00  0.00e+00
   max tail   7.97e-01  3.70e-01  2.94e-03  0.00e+00  0.00e+00  0.00e+00  0.00e+00
   argmax b         -1        -1        -1        -1        -1        -1        -1
