Let be the number of arrangements leaving *none of the*
*bins
empty* [28]. We imagine adding an additional bin. This bin contains k stones
(
) but not 0, so that we can express the number of arrangements
in the other bins with . Therefore, the number of arrangements
leaving *none of the* *bins empty* satisfies a recurrence,

**Figure 6:**
Composing the recurrence formula

Tiziano Mengotti 2004-03-27