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            • 1.

              在数列\(\left\{ {{a}_{n}} \right\}\)中,\({{a}_{{1}}}{+2}{{a}_{2}}+{{2}^{2}}{{a}_{3}}+\cdots +{{2}^{n-1}}{{a}_{n}}=(n\cdot {{2}^{n}}-{{2}^{n}}+1)\ t\)对任意\(n\in {{N}^{*}}\)成立,其中常数\(t > 0.\)若关于\(n\)的不等式\(\dfrac{1}{{{a}_{2}}}+\dfrac{1}{{{a}_{4}}}+\dfrac{1}{{{a}_{8}}}+\cdots +\dfrac{1}{{{a}_{{{2}^{n}}}}} > \dfrac{m}{{{a}_{1}}}\)的解集为\(\{n|n\geqslant 4,n\in {{N}^{*}}\}\),则实数\(m\)的取值范围是                   

            • 2.

              已知数列\(\left\{ {{a}_{n}} \right\}\)的通项公式\({{a}_{n}}=-n+t\),数列\(\left\{ {{b}_{n}} \right\}\)的通项公式\({{b}_{n}}={{2}^{n}}\),设数列\(\left\{ {{c}_{n}} \right\}\)满足\({{c}_{n}}=\dfrac{{{a}_{n}}+{{b}_{n}}}{2}+\dfrac{\left| {{a}_{n}}-{{b}_{n}} \right|}{2}\),且\({{c}_{n}}\geqslant {{c}_{3}}\left( n\in {{N}^{{*}}} \right)\),则实数\(t\)的取值范围是________________

            • 3. 已知数列\(\{a_{n}\}\)的前\(n\)项和为\(S_{n}\),且\(a_{1}=1\),\(a_{n+1}= \dfrac {1}{2}S_{n}\),则\(a_{5}=(\)  \()\)
              A.\( \dfrac {1}{16}\)
              B.\( \dfrac {1}{8}\)
              C.\( \dfrac {27}{16}\)
              D.\( \dfrac {81}{16}\)
            • 4. 已知数列\(\{a_{n}\}\)与\(\{b_{n}\}\)满足\(a_{n+1}-a_{n}=2(b_{n+1}-b_{n})\),\(n∈N^{*}\).
              \((1)\)若\(b_{n}=3n+5\),且\(a_{1}=1\),求\(\{a_{n}\}\)的通项公式;
              \((2)\)设\(\{a_{n}\}\)的第\(n_{0}\)项是最大项,即\(a_{n\_{0}}\geqslant a_{n}(n∈N*)\),求证:\(\{b_{n}\}\)的第\(n_{0}\)项是最大项;
              \((3)\)设\(a_{1}=3λ < 0\),\(b_{n}=λ^{n}(n∈N^{*})\),求\(λ\)的取值范围,使得对任意\(m\),\(n∈N^{*}\),\(a_{n}\neq 0\),且\( \dfrac {a_{m}}{a_{n}}∈( \dfrac {1}{6},6)\).
            • 5.

              已知数列\(\left\{ {{a}_{n}} \right\}\)满足:\({{a}_{1}}=1\),\({{a}_{n+1}}=\dfrac{{{a}_{n}}}{{{a}_{n}}+2}\) \(\left( n\in {{N}^{*}} \right).\)若\({{b}_{n+1}}=\left( n-2\lambda \right)\cdot \left( \dfrac{1}{{{a}_{n}}}+1 \right)\) \(\left( n\in {{N}^{*}} \right)\),\({{b}_{1}}=-\lambda \),且数列\(\left\{ {{b}_{n}} \right\}\)是单调递增数列,则实数\(\lambda \)的取值范围是____。

              A.\(\lambda > \dfrac{2}{3}\)
              B.\(\lambda > \dfrac{3}{2}\)
              C.\(\lambda < \dfrac{2}{3}\)
              D.\(\lambda < \dfrac{3}{2}\)
            • 6. 为等差数列, ,公差 ,则使前 项和 取得最大值时 \(=(\)    \()\)
              A.\(4\)或\(5\)      
              B.\(5\)或\(6\)        
              C.\(6\)或\(7\)       
              D.\(8\)或\(9\)
            • 7.

              已知数列\(\{a_{n}\}\)满足\({{a}_{n+1}}=\dfrac{1}{1-{{a}_{n}}}(n∈N*)\),\(a_{8}=2\),则\(a_{1}\)的值为\((\)    \()\)

              A.\(-1\)
              B.\(1\)
              C.\(\dfrac{1}{2}\).
              D.\(2.\)
            • 8. 数列\(\left\{ {{a}_{n}} \right\}\)的通项公式为\({{a}_{n}}=-2{{n}^{2}}+\lambda n(n\in {{N}^{*}},\lambda \in R)\),若\(\left\{ {{a}_{n}} \right\}\)是递减数列,则\(\lambda \)的取值范围是\((\)  \()\)
              A.\((-∞,4)\)   
              B.\((-∞,4]\)   
              C.\((-∞,6)\)   
              D.\((-∞,6]\)
            • 9.

              已知首项为\(\dfrac{3}{2}\)的等比数列\(\{{{a}_{n}}\}\)的前\(n\)项和为\({{S}_{n}}\),\((n\in {{N}^{*}})\),且\(-2{{S}_{2}},{{S}_{3}},4{{S}_{4}}\)成等差数列,

              \((\)Ⅰ\()\)求数列\(\{{{a}_{n}}\}\)的通项公式;

              \((\)Ⅱ\()\)求\({{S}_{n}}(n\in {{N}^{*}})\)的最值.

            • 10.

              数列\(\left\{ {{a}_{n}} \right\}\)满足\({a}_{n+1}=\begin{cases}2{a}_{n},(0\leqslant {a}_{n} < \dfrac{1}{2}) \\ 2{a}_{n}-1,( \dfrac{1}{2}\leqslant {a}_{n} < 1)\end{cases} \),若\({{a}_{1}}=\dfrac{3}{5}\),则\({{a}_{2014}}=\)(    )

              A.\(\dfrac{1}{5}\)
              B.\(\dfrac{2}{5}\)
              C.\(\dfrac{3}{5}\)
              D.\(\dfrac{4}{5}\)
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