9-1=8;16-4=12;25-9=16;36-16=20;… What laws do these equations reflect among positive integers

9-1=8;16-4=12;25-9=16;36-16=20;… What laws do these equations reflect among positive integers

9-1 = 8; that is, 3 & # 178; - 1 & # 178; = (3 + 1) × (3-1) = 4 × 216-4 = 12; that is, 4 & # 178; - 2 & # 178; = (4 + 2) × (4-2) = 6 × 225-9 = 16; that is, 5 & # 178; - 3 & # 178; = (5 + 3) × (5-3) = 8 × 2; 36-16 = 20, that is, 6 & # 178; - 4 & # 178; = (6 + 4) × (6-4) = 10 × 2