Can we sum $r(r+1)(r+3)$ for $r$ from $1$ to $n$?

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Evaluate:

2. \(\sum_{r=1}^n \dfrac{1}{r(r+1)(r+3)}\).

How can we rewrite \(\dfrac{1}{r(r+1)(r+3)}\) in a way that might be useful? Could we use partial fractions?

Or alternatively, if we write the numerator as \(r+1-r\), can we now split the fraction into two fractions which both have terms that cancel?