# Python Program for sum of squares of n natural numbers

In this article, we will learn to find the sum of the square of the first n number using the python program.

We find the sum of the square of positive numbers from 1 to nth using two methods:

• using for loop
• using mathematical formula

the sum of the square of n numbers:

12 + 22 + 32 + 42 + ....... + (n-1)2 + n2

### Method 1: Using for loop

Time Complexity for this program is: O(N)

#### Program

 ``` 1 2 3 4 5 6 7 8 9 10``` ```# Sum of the square of positive numbers from 1 to nth using forloop n = int(input("Enter nth number: ")) sum = 0 for i in range(1,n+1): sum = sum + (i*i) print("Sum of the square of the number from 1 to",n,"is: ",sum) # Sum of the square of positive numbers from of nth using forloop - docodehere.com ```

#### Output

```Enter nth number: 10
Sum of the square of the number from 1 to 10 is:  385
```

### Method 2: Using Mathematical formula

Time Complexity for this program is: O(1)

#### Program

 ```1 2 3 4 5 6``` ```# Sum of the square of positive numbers from 1 to nth without forloop n = int(input("Enter nth number: ")) print((n * (n + 1) / 2) * (2 * n + 1) / 3) # Sum of the square of positive numbers from of nth without forloop - docodehere.com ```

#### Output

```Enter nth number: 2
5
```
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