将数列3,6,9,……按照如下规律排列,
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/9/358950f2-54bf-4632-80f4-dcd50ea393f8.png?resizew=158)
记第
行的第
个数为
,如
,若
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/934d37c81b2266c7b86bcc11afaf5f91.png)
_______ .
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/9/358950f2-54bf-4632-80f4-dcd50ea393f8.png?resizew=158)
记第
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6bd6ea203b33202a21fc7c3d3813486.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9eea1a6e85aa32a9bedd627fe31bbca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6b6742d38cb59340109644fbcd2ce18.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/934d37c81b2266c7b86bcc11afaf5f91.png)
更新时间:2019-03-19 23:21:39
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【知识点】 根据规律填写数列中的某项
相似题推荐
【推荐1】观察下面的数阵,第20行最左边的数是_____________ .
1
2 3 4
5 6 7 8 9
10 11 12 13 14 15 16
17 18 19 20 21 22 23 24 25
1
2 3 4
5 6 7 8 9
10 11 12 13 14 15 16
17 18 19 20 21 22 23 24 25
…… …… …… …… ……
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【推荐2】把正整数排列成如图甲的三角形数阵,然后擦去第偶数行的奇数和第奇数行中的偶数,得到如图乙的三角数阵,再把图乙中的数按从小到大的顺序排成一列,得到数列
,若
,则
的值为__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f71aceb2db4ab06482a6802a37aaa564.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/13/3d536b23-330a-4099-855c-5b22767da049.png?resizew=573)
您最近一年使用:0次