How to Find Sum of Squares of First N Natural Numbers in Python

Submitted by razormist on Saturday, May 30, 2026 - 22:51.

In this tutorial, we will learn how to program "How to Find Sum of Squares of First N Natural Numbers in Python". The objective is to find the sum of squares of the first N natural numbers. This tutorial will guide you step by step through the process of finding the sum of squares of the first N natural numbers. By the end of this tutorial, you will have a solid understanding of how to implement this solution effectively in Python, helping you strengthen your problem-solving abilities and improve your coding skills.

This topic is straightforward and easy to understand. By following the instructions provided, you will be able to complete it with ease. The program will guide you step by step through the process of finding the sum of squares of the first N natural numbers. So, let’s dive into the coding process!

Getting Started:

First you will have to download & install the Python IDLE's, here's the link for the Integrated Development And Learning Environment for Python https://www.python.org/downloads/.

Creating Main Function

This is the main function of the application. The following code will display a simple GUI in terminal console that will display program. To do this, simply copy and paste these blocks of code into the IDLE text editor.

# MAIN LOOP
while True:
    print("\n============= Find Sum of Squares of First N Natural Numbers =============\n")
 
    # Input value of n
    try:
        n = int(input("Enter a positive integer (n): "))
 
        if n <= 0:
            print("Please enter a positive integer greater than 0.")
            continue
 
    except ValueError:
        print("Invalid input. Please enter an integer.")
        continue
 
    # Calculate sum of squares
    res = n * (n + 1) * (2 * n + 1) // 6
 
    print(f"\nThe sum of squares of the first {n} natural numbers is: {res}")
 
    # Try Again Option
    opt = input("\nDo you want to try again? (yes/no): ").strip().lower()
 
    if opt == 'no':
        print("Exiting program...")
        break
    elif opt != 'yes':
        print("Invalid choice. Exiting program...")
        break

This Python program calculates the sum of squares of the first N natural numbers using a mathematical formula instead of iteration. It takes a positive integer input `n`, validates it, and computes the result using the formula ( n(n+1)(2n+1)/6 ). The program then displays the result and runs interactively, allowing users to repeat the process or exit, with input validation included.

Output:

There you have it we successfully created How to Find Sum of Squares of First N Natural Numbers in Python. I hope that this simple tutorial help you to what you are looking for. For more updates and tutorials just kindly visit this site. Enjoy Coding!

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