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Given:
S=n=2∑∞(n2−1)33n2+1
We start by recognizing that:
(n2−1)3=(n−1)3(n+1)3
Additionally:
(n+1)3−(n−1)3=6n2+2
Now, we can express the series as follows:
S=n=2∑∞21((n+1)3(n−1)3(n+1)3−(n−1)3)
Rewriting the sum, we get:
S=21n=2∑∞((n−1)31−(n+1)31)
This can be expanded as a telescoping series:
S=21((131−331)+(231−431)+(331−531)+…)
The terms 331,431,… cancel out in the series, leaving us with:
S=21(131+231)
Simplifying further:
S=21(1+81)=21(89)=169
Thus,
16S=16⋅169=9
Therefore, the value of 16S is:
9