The number of combinations (each number used only once and in one order) is 24. Since the numbers can be used more than once (and in any order), it is the number of permutations that is if interest. The number of permutations is 5!/(5-5)!=120. So, there is one sequence that cannot be changed (the factory set code) and one that can be any of 120 permutations (including the factory set code).