[math-fun] (x^6-1)/(x^2-x+1) via pebbles

Can anyone steer me toward an online (You-tube?) video of someone using pebble-moves to prove that x^6 - 1 is a multiple of x^2 - x + 1, by starting with a single pebble and managing to move it six spaces to the left (or maybe it was to the right?) with moves that replace a pebble at n with pebble at each of n-1 and n+1, and other moves that do the reverse? Thanks, Jim Propp