# Find the sum of N terms of the series 1^2, (1^2+2^2), (1^2+2^2+3^2), …..

• Last Updated : 17 Jul, 2022

Given a positive integer, N. Find the sum of the first N term of the series-

12, (12+22), (12+22+32),….,till N terms

Examples:

Input: N = 3

Output: 20

Input: N = 1

Output: 1

Approach: The sequence is formed by using the following pattern. For any value N-

Given 1^2, (1^2+2^2), (1^2+2^2+3^2),….,till N terms SN = N * (N+1)2 * (N+2) / 12

Below is the implementation of the above approach:

## C++

 // C++ program to implement// the above approach #include using namespace std; // Function to return sum of// N term of the series int findSum(int N){    return N*(N+1)*(N+1)*(N+2)/12;   } // Driver Code int main(){    int N = 3;         cout << findSum(N);}

## Java

 // Java program to implement// the above approach class GFG {     // Function to return sum of    // N term of the series     static int findSum(int N) {         return N * (N + 1) * (N + 1) * (N + 2) / 12;     }     // Driver Code     public static void main(String args[]) {        int N = 3;         System.out.print(findSum(N));    }} // This code is contributed by Saurabh Jaiswal

## Python3

 # Python 3 program for the above approach # Function to return sum of# N term of the series def findSum(N):     return N*(N+1)*(N+1)*(N+2)//12  # Driver Codeif __name__ == "__main__":       # Value of N    N = 3       print(findSum(N)) # This code is contributed by Abhishek Thakur.

## C#

 // C# program to implement// the above approachusing System;class GFG{ // Function to return sum of// N term of the series static int findSum(int N){    return N*(N+1)*(N+1)*(N+2)/12;   } // Driver Code public static void Main(){    int N = 3;         Console.Write(findSum(N));}} // This code is contributed by Samim Hossain Mondal.

## Javascript

 

Output

20

Time Complexity: O(1)
Auxiliary Space: O(1)

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