1/3单选题
难度：
1.数列{an}中，
=2,
-
=2n,
,则
=( )
=2,-=2n,,则=( ) | A | 9900 |
| B | 9902 |
| C | 9904 |
| D | 9906 |
正确答案：Qg==
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
+
,数列{ an }的通项公式( ) 
(
)
)
)
(
),