1, 2, 4
5, 6, 7
8, 9, 10
11, 12, 13
15, 16, 17
20, 21, 22
23, 24, 25 
28, 29, 30
31, 32, 33
36, 37, 38
39, 40, 41
44, 45, 46
47, 48, 49
51, 52, 53
54, 55, 56
58, 59, 60
