名校
解题方法
1 . 已知数列![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f155247fc662b89c545ea34094b778d6.png)
,
,…,
的各项均为正整数.设集合,
记
的元素个数为
.
(1)若数列
1,1,3,2,求集合
,并写出
的值;
(2)若
是递增数列,求证:“
”的充要条件是“
为等差数列”;
(3)若
,数列
由1,2,3,…,11,22这12个数组成,且这12个数在数列
中每个至少出现一次,求
的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f155247fc662b89c545ea34094b778d6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e88093a749c0d46e0ee931ecfaff925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d8e6e9e456eb7ed9de302990075d1c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3093d1159a994b153db26d1ba23c567f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b68df477b3ee45ac0f725db00d465a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a318eb5a4da016d3d993175e845a90ab.png)
(1)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f155247fc662b89c545ea34094b778d6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b68df477b3ee45ac0f725db00d465a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a318eb5a4da016d3d993175e845a90ab.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be63af01fc637c108801b34882acc1a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/807511534842b45a837c0fe12754345e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a318eb5a4da016d3d993175e845a90ab.png)
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