已知数列
,
,
,
,
,…,这个数列的特点是从第二项起,每一项都等于它的前后两项之和,则这个数列的前
项之和
= ______ .
![](https://img.xkw.com/dksih/QBM/2011/12/27/1570635179106304/1570635184553984/STEM/676dd3d21dbc462889bedb8a7a428c97.png?resizew=37)
![](https://img.xkw.com/dksih/QBM/2011/12/27/1570635179106304/1570635184553984/STEM/222ff512e8a14ec49edc26f417ee72f6.png?resizew=37)
![](https://img.xkw.com/dksih/QBM/2011/12/27/1570635179106304/1570635184553984/STEM/9fc6957ca9ec49dab63c01376a2ed0ba.png?resizew=9)
![](https://img.xkw.com/dksih/QBM/2011/12/27/1570635179106304/1570635184553984/STEM/a08608d09bab4576a003d75625dca3d7.png?resizew=49)
![](https://img.xkw.com/dksih/QBM/2011/12/27/1570635179106304/1570635184553984/STEM/8c639b2834994de2825df988cfebc58b.png?resizew=49)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb8b5f0ffe0a3eec01f91f2e9a5db687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/258cb9187f4d464ba98ccd9eff1b89fc.png)
2010高二·海南·学业考试 查看更多[2]
更新时间:2016-11-30 03:34:56
|
【知识点】 数列周期性的应用
相似题推荐
填空题-单空题
|
较易
(0.85)
解题方法
【推荐2】在数列
中,已知
,
,记
为数列
的前
项和,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e472ad6e7bf7a6a409a43d4ea9035e0.png)
________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33362cb770e46d6af6268e1d7999d2a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e472ad6e7bf7a6a409a43d4ea9035e0.png)
您最近一年使用:0次