63, 126 and 189 and the first three I can think of. Confirmed in excel.
140,280,420
The least common multiples of 7 and 14 are 14,28 and 42>
Common multiples of 7 and 5 include 35, 70, 140, etc.
Here are some common multiples of 12 and 7 84, 168, 1008 and 12096.
The first 3 multiples of 7 are: 7, 14, and 21.
7, 14, 21
21
63
42, 84 and 126
56, 112, 168
14, 28, 42
14, 28, 42.
14, 28, 42.
63, 126, 189.
14, 28, 42
140, 280, 420
140, 280, 420