Find the sum of n terms of the series whose nth term is: `n(n+3)`

Explanation

To find the sum of the first \( n \) terms of the series whose \( n \)th term is given by \( t_n = n(n + 3) \), we can follow these steps:

### Step 1: Identify the nth term
The \( n \)th term of the series is given by:
\[ t_n = n(n + 3) = n^2 + 3n \]

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