Add 3 1, and the rule is as follows: the difference between 1 and 3 is 2, the difference between 7 and 3 is 4, and the difference between 15 is 8, so the difference between them is exactly the n power of 2. It is inferred that the difference between 3 1, 3 1 and 63 is 32, which is the fifth power of 2, 365438.