$\"\"$

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The sequence is $\"\"$ and $\"\"$ .

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Above sequence substitute $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$ (Substitute n = 1)

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$\"\"$

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$\"\"$ (Substitute n = 2)

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$\"\"$

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$\"\"$ (Substitute n = 3)

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$\"\"$

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$\"\"$

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The value of $\"\"$ .