Numbers are obtained when the product of an integer's digits divided by
the sum of its digits is itself an integer. If the resultant
integer can be used to produce yet another integer in the same way, a
sequence is formed. It is terminated when a new term is less than
10. The first term must be at least 10, or an endless loop is
Find the lowest starting term for a sequence of two ProSum Numbers, then do the same for three terms and four terms.