Consider a game of Tower of Hanoi (like the one that you can play on BrainVista). If the tower has 2 discs, the least possible moves with which you can move the entire tower to another peg is 3. If the tower has 3 discs, the least possible moves with which you can move the entire tower to another peg is 7. What is the least possible moves with which you can move the entire tower to another peg if the tower has N discs?