已知
,把数列
的各项排成如下的三角形:
![](https://img.xkw.com/dksih/QBM/2018/4/23/1930119614447616/1933365130248192/STEM/ce34783dad5943549eb92d64dd67dac1.png?resizew=150)
记
表示第
行的第
个数,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b596bb22191e1e53e8623f6cf94df327.png)
___ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac7f82f00fe6163833431241820687ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://img.xkw.com/dksih/QBM/2018/4/23/1930119614447616/1933365130248192/STEM/ce34783dad5943549eb92d64dd67dac1.png?resizew=150)
记
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a2a5a68b6ca168116768ba353c9dcdf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5873c01192b7d33b7483f444f90b5b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b596bb22191e1e53e8623f6cf94df327.png)
更新时间:2018-04-27 23:04:20
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【推荐1】已知
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【推荐2】某校学生在研究民间剪纸艺术时,发现剪纸时经常会沿纸的某条对称轴把纸对折,规格为
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