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            • 1.

              设数列\(\{a_{n}\}\)的首项\(a_{1}=1\),且满足\(a_{2n+1}=2a_{2n-1}\)与\(a_{2n}=a_{2n-1}+1\),则\(S_{20}=\)              \(.\) 

            • 2.

              数列\(\left\{ {{a}_{n}} \right\}\)满足\({{a}_{1}}{=}1\),\(n{{a}_{n+1}}{=}\left( n+1 \right){{a}_{n}}+n\left( n+1 \right)\),且\({{b}_{n}}{=}{{a}_{n}}\cos \dfrac{2n\pi }{3}\),记\({{S}_{n}}\)为数列\(\left\{ {{b}_{n}} \right\}\)的前\(n\)项和,则\({{S}_{120}}=\)_______.

            • 3.

              已知等差数列\(\{a_{n}\}\)的公差\(d\neq 0\),且\(a_{1}\),\(a_{3}\),\(a\)\(13\)成等比数列,若\(a_{1}=1\),\(S_{n}\)是数列\(\{a_{n}\}\)前\(n\)项的和,则\(\dfrac{2{{S}_{n}}+16}{{{a}_{n}}+3}(n∈N^{*})\)的最小值为______.

            • 4.

              已知数列\(\left\{ a_{n} \right\}\)的前\(n\)项和\(S_{n}=\left( \mathrm{{-}}1 \right)^{n\mathrm{{-}}1}·n\),若对任意的正整数\(n\),有\((a_{n+1}-p)(a_{n}-p) < 0\)恒成立, 则实数\(p\)的取值范围是____\(.\) 

            • 5.

              已知数列\(\{a_{n}\}\),\(a_{1}=1\),\(a_{n+1}=2a_{n}+2\),则\(a_{n}=\)          ,\(S_{n}=\)             

            • 6. \(15.\)定义等积数列:若\((p\)为非零常数, \()\),则称为等积数列,\(P\)称为公积\(.\)若为等积数列,公积为\(1\),首项为\(a\),前\(n\)项和为,则  ______.



            • 7.

              数列\(\left\{ {{a}_{n}} \right\}\)的通项\({{a}_{n}}={{n}^{2}}({{\cos }^{2}}\dfrac{n\pi }{3}-{{\sin }^{2}}\dfrac{n\pi }{3})\),其前\(n\)项和为\({{S}_{n}}\),则\({{S}_{30}}\)为_______

            • 8. 若数列\(\{a_{n}\}\)满足\(a_{n}-(-1)^{n}a_{n-1}=n(n\geqslant 2)\),\(S_{n}\)是\(\{a_{n}\}\)的前\(n\)项和,则\(S_{40}=\)________.
            • 9. 设数列\(\{a_{n}\}\)首项\(a_{1}=2\),前\(n\)项和为\(S_{n}\),且满足\(2a_{n+1}+S_{n}=3(n∈N^{*})\),则满足\( \dfrac {34}{33} < \dfrac {S_{2n}}{S_{n}} < \dfrac {16}{15}\)的所有\(n\)的和为______
            • 10.

              设\(S_{n}\)为数列\(\{a_{n}\}\)的前\(n\)项和,若不等式\({{n}^{2}}a_{n}^{2}+4S_{n}^{2}\geqslant \lambda {{n}^{2}}a_{1}^{2}\)对任意等差数列\(\{a_{n}\}\)及任意正整数\(n\)恒成立,则\(λ\)的最大值为________.

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