There are many solutions. But what do you mean with a perfect square of a number. I thought a number IS a perfect square or not.
For example, the difference between 2² and 4² = 12, which is twice the number 6, which is √36
The difference between 2² and 6² = 32, which is twice the number 16, which is a perfect square.
So choose depending on your interpretation of the question... ;-)
