2 = 2
2 + 2 = 4
2 + 2 + 2 = 6
2 + 2 + 2 + 2 = 8
2 + 2 + 2 + 2 + 2 = 10
2 + 2 + 2 + 2 + 2 + 2 = 12
2 + 2 + 2 + 2 + 2 + 2 + 2 = 14
2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 = 16
2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 = 18
2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 + 2 = 20