This is a recursive function: It forms the \(\mu\)-cube by
joining two (\(\mu-1\))-cubes vertex by vertex, starting from
the 1-cube, which is \(K_1\), a single vertex with no edges.
The \(\mu\)-cube has \(2^\mu\) vertices and
\(\mu\times2^{\mu-1}\) edges, so it is exponentially big in
\(\mu\), please consider this when creating a \(\mu\)-cube
with moderate \(\mu\) (and don't create any cube
with large \(\mu\)).