The minimum sum is 3 and the maximum is 11. So there are 9 different possible sums. There are 30 ways to get these 9 different sums. The table below shows all outcomes.
1 2 3 4 5 6 ———————————- 1 | X 3 4 5 6 7 2 | 3 X 5 6 7 8 3 | 4 5 X 7 8 9 4 | 5 6 7 X 9 10 5 | 6 7 8 9 X 11 6 | 7 8 9 10 11 X