This will be true for any three consecutive integers.
Suppose the middle one is "a".
The product of the other two is (a-1)*(a+1) = a^2 - 1. The square of the middle number, a^2, is greater than this amount by 1, regardless of the value of "a".
Suppose the middle one is "a".
The product of the other two is (a-1)*(a+1) = a^2 - 1. The square of the middle number, a^2, is greater than this amount by 1, regardless of the value of "a".