Given the value of n, we need to find the sum of the series where i-th term is sum of first i natural numbers.
NOTE: Sum of the series 1 + (1+2) + (1+2+3) + (1+2+3+4) + …… + (1+2+3+4+…+n)
Example 1:
Input: n = 5
Output: 35
Explanation: 1 + (1+2) + (1+2+3).. = 35
Hence sum of the series is 35.
Example 2:
Input: n = 10
Output: 220
Explanation: 1 + (1+2) + (1+2+3) +
(1+2+3+4) + (1+2+3+4+5)... = 210.
Hence sum of the series is 210.
Your Task:
You dont need to read input or print anything. Complete the function sumOfTheSeries() which takes n as input parameter and returns the sum of the series of n terms.
Expected Time Complexity: O(1)
Expected Auxiliary Space: O(1)
Constraints:
1<= n <=1000

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