$\"\"$

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The $\"\"$ term of the sequence $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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Apply formula: $\"\"$ .

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Here $\"\"$ .

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$\"\"$ .

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$\"\"$

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Therefore, the sequence is converges to $\"\"$ .

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$\"\"$

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The sequence is convergence to $\"\"$ .