题干
设等差数列{an}的公差d＞0，且a1＞0，记Tn=
+
++
．
| 1 |
| a |
| 1 |
| a |
| 2 |
| 1 |
| a |
| 2 |
| a |
| 3 |
| 1 |
| a |
| n |
| a |
| n |
| + |
| 1 |
