(本小題滿分14分) 設(shè)數(shù)列
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的前n項和為
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,點
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均在函數(shù)y=3x-2的圖像上。
(Ⅰ)求數(shù)列
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的通項公式;
(Ⅱ)設(shè)
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,
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是數(shù)列
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的前n項和,求使得
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對所有
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都成立的最大正整數(shù)
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.
解:(I)依題意得,
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即
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。
當(dāng)n≥2時,
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;
當(dāng)
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所以
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。
(II)由(I)得
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,
故
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=
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。
因此,使得
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>
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成立的m必須滿足
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,
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,
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故滿足要求的最大整數(shù)m為8.
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
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
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
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