Observe the following equations: 9-1 = 8,16-4 = 12,25-9 = 16,36-16-20, ', try the equation about n to express the law you found

Observe the following equations: 9-1 = 8,16-4 = 12,25-9 = 16,36-16-20, ', try the equation about n to express the law you found

(n+2)^2-n^2=4(n+1)