Maximum length sequence

Maximum length sequence is a way of arranging numbers. There is a certain set of numbers and you have to arrange them in a certain way so that there is the longest possible sequence of numbers. For example, if the set was 1, 2, 3, 4, 5, your maximum length sequence might be 1, 2, 4, 5, 3. That sequence has 5 numbers in it, so it is the maximum length.