Towers of Hanoi 1
Peg A has n disks, starting with the largest one on the bottom and successively smaller ones on top.
The object of the puzzle is to move the disks one at a time from peg to peg, never placing a larger one on top of a smaller one, eventually ending with all the disks on peg B
Solution1: Imagine the pegs arranged in a triangle. On odd numbered moves, move the smallest disk one peg clockwise. On even numbered moves make the only legal move not involving the smallest disk.