I am trying to solve a puzzle. How do I find an algorithm (or a formula) behind a series of six two-digit numbers? (The numbers are as follows: 14, 21, 33, 41, 56, 68.) The two-digit numbers, although different from one another, are always the same ones given. Each time they are rearranged differently. I have been given 45 instances of these six two-digit numbers. I need to calculate the next sequence, the forty-sixth. Is there a formula (an algorithm) to determine the answer? Any help warmly received.