My First Problem

Algebra Level pending

f(k) = 1+ $$\frac{1}{2}$$ + $$\frac{1}{3}$$ + $$\ldots$$ + $$\frac{1}{k}$$.

Find $$\displaystyle\sum_{k=1}^n$$ (2k+1)f(k)

For n=11 . Given that f(11)=3

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