2*(2n+ 1)=a^2-b^2=(a+b)(a-b)
Obviously, a+b and a-b have the same parity.
The left is even, so (a+b)(a-b) is even.
Therefore, a+b and a-b are even numbers, and the right side of the equation can be divisible by 4, but the left side of the equation cannot be divisible by 4, which is contradictory.
So 2*(2n+ 1) cannot be expressed as the square difference of two integers.
(1) Please refer to the following table for the differences between lines,