max-min=5.
(6/6)^n-2(5/6)^n+(4/6)^n.
max-min=4.
(5/6)^n-2(4/6)^n+(3/6)^n.
max-min=3.
(4/6)^n-2(3/6)^n+(2/6)^n.
max-min=2.
(3/6)^n-2(2/6)^n+(1/6)^n.
max-min=1.
(2/6)^n-2(1/6)^n+(0/6)^n.
max-min=0.
(1/6)^n-(0/6)^n.
max-min<0.
(0/6)^n.

2(5/6)^n-3(4/6)^n+2(3/6)^n-(2/6)^n.