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            • 1.
              已知数列\(\{a_{n}\}\)的前\(n\)项和为\(S_{n}\),且满足\(S_{n}=(-1)^{n}\cdot a_{n}- \dfrac {1}{2^{n}}\),记\(b_{n}=8a_{2}\cdot 2^{n-1}\),若对任意的\(n∈N^{*}\),总有\(λb_{n}-1 > 0\)成立,则实数\(λ\)的取值范围为 ______ .
            • 2.
              已知数列\(\{a_{n}\}\)的前\(n\)项和为\(S_{n}\),\(a_{1}=1\),且满足\(a_{n}a_{n+1}=2S_{n}\),数列\(\{b_{n}\}\)满足\(b_{1}=15\),\(b_{n+1}-b_{n}=2n\),则数列\(\{ \dfrac {b_{n}}{a_{n}}\}\)中第 ______ 项最小.
            • 3.
              设\(f(x)=f_{1}(x)= \dfrac {x}{1+x},f_{n}(x)=f_{n-1}[f(x)](n\geqslant 2,n∈N_{+})\),则\(f(1)+f(2)+…+f(n)+f_{1}(1)+f_{2}(1)+…+f_{n}(1)=\) ______ .
            • 4.
              已知数列\(\{ \sqrt {a_{n+1}}- \sqrt {a_{n}}\}\)是公差为\(2\)的等差数列,且\(a_{1}=1\),\(a_{3}=9\),则\(a_{n}=\) ______ .
            • 5.

              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                   

            • 6.

              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________________

            • 7.

              已知数列\(\{{{a}_{n}}\}\)中,\({{a}_{1}}=1\),\({{a}_{n+1}}=c+\dfrac{1}{{{a}_{n}}}\),且\(1\leqslant {{a}_{n}}\leqslant 4\),则\(c\)的取值范围是___\(.\) 

            • 8.

              已知数列\(\{a_{n}\}\)的通项公式\({a}_{n}=\left(n+2\right)·{\left( \dfrac{3}{4}\right)}^{n} \),则数列\(\{a_{n}\}\)的项取最大值时,\(n=\)_____.

            • 9.

              已知各项均为正数的数列\(\{{{a}_{n}}\}\)且满足\({{a}_{1}}=\dfrac{7}{2}\),\(\{{{a}_{n}}-\dfrac{1}{2}\}\)是公比为\(\dfrac{1}{2}\)的等比数列,\({{S}_{n}}\)为数列\(\{{{a}_{n}}\}\)的前\(n\)项和,若对于任意的\(n\in {{N}^{*}}\),\(\dfrac{12k}{12+n-2{{S}_{n}}}\geqslant 2n-3\)恒成立,则实数\(k\)的取值范围_____________.

            • 10.

              函数\(f\left( x \right)=\dfrac{{{\log }_{3}}\left( x+1 \right)}{x+1}\left( x > 0 \right)\)的图象上有一点列\({{P}_{n}}\left( {{x}_{n}},{{y}_{n}} \right)(n{∈}N_{{+}})\),点\({{P}_{n}}\)\(x\)轴上的射影\({{Q}_{n}}\left( {{x}_{n}},0 \right)\),且\({{x}_{n}}=3{{x}_{n-1}}+2\)\((\)\(n{\geqslant }2\)\(n{∈}N\)\()\),\({{x}_{1}}=2\)

              \((1)\)求出数列\(\left\{ {{x}_{n}} \right\}\)的通项公式;

              \((2)\)对任意的正整数\(n\),当\(m{∈}{[}{-}1{,}1{]}\)时,不等式\(3{{t}^{2}}-6mt+\dfrac{1}{3} > {{y}_{n}}\)恒成立,求实数\(t\)的取值范围;

              \((3)\)设四边形\({{P}_{n}}{{Q}_{n}}{{Q}_{n+1}}{{P}_{n+1}}\)的面积是\({{S}_{n}}\),求证:\(\dfrac{1}{S_{1}}{+}\dfrac{1}{{2S}_{2}}{+}{…}{+}\dfrac{1}{{nS}_{n}}{ < }\dfrac{5}{4}\).

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