在數(shù)列
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025102753457.png)
中,若
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025102769371.png)
,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025102769872.png)
,則該數(shù)列的通項
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025102785373.png)
________________.
試題分析:
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025102816953.png)
,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025102831596.png)
是首項為4,公比為2的等比數(shù)列,所以
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025102863752.png)
,所以
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824025102878486.png)
.
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