***** a4,1 *****

5 cosets
2 double cosets
Sizes:
0: ()
      [1]	1
1: (1)
      [4]	q + q^2 + q^3 + q^4

Neighbours of a point in 0:
1:  [4]		q + q^2 + q^3 + q^4

Neighbours of a point in 1:
0:  [1]		1
1:  [3]		-1 + q + q^2 + q^3 + q^4