A permutation on permutations

[Tyler Eaves]

Arthur Siegel wrote:

> Was able to find nice stuff on the python-list archives
> as to list permutations, list reversal, and removing
> duplicates from lists.
> 
> My problem is to combine them.
> 
> I am feeding control points to a curve function, and
> want all permutations that result in unique curves.
> For this purpose a sequence is duplicative
> of its reverse, i.e. [1,2,3,4] == [4,3,2,1], etc.
> 
Would [1,3,2,4] be a duplicate?