Find the sum of the first n terms of the series :
`3 + 7 + 13 +21 + 31 +..........`

Explanation

To find the sum of the first \( n \) terms of the series \( 3 + 7 + 13 + 21 + 31 + \ldots \), we will follow these steps:

### Step 1: Identify the Pattern
First, we need to identify the pattern in the series. Let's write down the terms:
- \( a_1 = 3 \)
- \( a_2 = 7 \)
- \( a_3 = 13 \)
- \( a_4 = 21 \)
...