Example 1 Let be a given positive integer, and each term of the sequence is a positive integer, and for any , we have . Prove: There exist infinitely many pairs of positive integers , such that , and .
Solution
Proof
First, we prove that there exists a pair that satisfies the condition.
Consider the following number table:
where . And
The numbers in the above table have the following properties: each row from left to right is exactly a sequence of consecutive positive integers; in any two numbers in each column, the smaller number (let it be ) is a divisor of the larger number, i.e., .
Since , each row of the table contains at least two terms from , so the table contains at least numbers . Therefore, there must be a column in the table that contains two numbers simultaneously belonging to , denoted as , then . Thus, we have found a pair that satisfies the condition.
Now, set to , and construct a number table with the same properties. We can find another pair of numbers that satisfy the condition. By continuing this process, we can find infinitely many pairs such that and .
The proposition is proved.