The README explains the splitting section incorrectly

[but0n]

You can control how many times the split is performed by using the --divisions flag. The model will be split into divisions^2 meshes (or divisions^3 if --zsplit is used).

If I understand correctly, a recursive division produces 2^(divisions*dimensions) meshes, not divisions^2. According to the description here:

For every decimated mesh, the program splits it recursively along x, y and z axis

Looking at the generated result, -d 4 gives a 16x16 grid, 256 meshes (2 ** (4 * 2)), which confirms the above logic.