如图所示的数表:第n行有n个数,且首尾两个数均为n.
| 1 |
| 2 |
| 2 |
| 5 |
| 3 |
| 10 |
| 4 |
| 17 |
| 1 |
| 3 |
| 1 |
| 5 |
| 1 |
| 7 |
| 1 |
| 9 |