
EXAMPLE

Label the vertices of a regular ngon 1,2,...,n.
For n=3,4,5 representatives for the polygons counted here are:
(1,2,3,1),
(1,2,3,4,1), (1,2,4,3,1),
(1,2,3,4,5,1), (1,2,3,5,4,1), (1,2,4,5,3,1), (1,3,5,2,4,1).
For n=6:
(1,2,3,4,5,6,1), (1,2,3,4,6,5,1), (1,2,3,5,6,4,1), (1,2,3,6,5,4,1),(1,2,4,3,6,5,1), (1,2,4,6,3,5,1), (1,2,4,6,5,3,1), (1,2,5,3,6,4,1),(1,2,5,4,6,3,1), (1,2,5,6,3,4,1), (1,2,6,4,5,3,1), (1,3,5,2,6,4,1).
