Find the law 3 ^ 2 = 4 + 5, 5 ^ 2 = 12 + 13, 7 ^ 2 = 24 + 25, find the law, and prove the method

Find the law 3 ^ 2 = 4 + 5, 5 ^ 2 = 12 + 13, 7 ^ 2 = 24 + 25, find the law, and prove the method

Square of odd = (odd * odd - 1) / 2 + (odd * odd + 1) / 2
That is n & # 178; = (n & # 178; - 1) / 2 + (n & # 178; + 1) / 2
prove:
Right = n & # 178 / 2-1 / 2 + n & # 178 / 2-1 / 2 = n & # 178; = left