Peeling Sequences

Given a set of n labeled points in general position in the plane, we remove all of its points one by one. At each step, one point from the convex hull of the remaining set is erased. In how many ways can the process be carried out? The answer obviously depends on the point set. If the points are in convex position, there are exactly n ! ways, which is the maximum number of ways for n points. But what is the minimum number? It is shown that this number is (roughly) at least 3ⁿ 3 n and at most 12.29ⁿ 12 . 29 n .