The n Disks on peg A are to be moved to peg C, but only one can be moved at a time and larger disks cannot be put on to smaller ones : peg B can be used.
The moves are determined by
To move n disks from X to Y
if n>0
Move n-1 disks from X to other
Move nth disk from X to Y
Move n-1 disks from other to Y