Find the sum to n terms of the series :`1 xx 2 + 2 xx 3 + 3xx4 + 4xx5+. . . . . .`

Explanation

To find the sum to n terms of the series \( 1 \times 2 + 2 \times 3 + 3 \times 4 + 4 \times 5 + \ldots \), we can follow these steps:

### Step 1: Identify the nth term of the series
The series can be expressed in terms of n as follows:
- The first term is \( 1 \times 2 = 2 \)
- The second term is \( 2 \times 3 = 6 \)
- The third term is \( 3 \times 4 = 12 \)
- The fourth term is \( 4 \times 5 = 20 \)
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