题干
已知各项为正数的数列{an}的前n项和为Sn，且满足 2Sn =
| a |
| n |
| + |
| 2 |
| 2 |
（Ⅰ）求证：{an}为等差数列，并求数列{an}的通项公式；
（Ⅱ）设 bn=
+
+⋯+
+
(n∈N* ) ，求证： bn≤
．
| 1 |
| a |
| n |
| + |
| a |
| 1 |
| 1 |
| a |
| n |
| + |
| a |
| 2 |
| 1 |
| a |
| n |
| + |
| a |
| n |
| 1 |
| a |
| n |
| + |
| a |
| n |
| + |
| 1 |
| 3 |
| 8 |
答案(点此获取答案解析）
证明：（Ⅰ）∵满足
