# C Program to Find Sum of series 1²+2²+3²+….+n²

In this tutorial, i am going to show you how to find sum of series 1²+2²+3²+….+n² with the help of a standard formula, for loop, function, and recursion in c programs.

## All C Programs to Find Sum of series 1²+2²+3²+….+n²

• C Program to Find Sum of series 1²+2²+3²+….+n² using Standard Formula
• C Program to Find Sum of series 1²+2²+3²+….+n² using For Loop
• C Program to Find Sum of series 1²+2²+3²+….+n² using Function
• C Program to Find Sum of series 1²+2²+3²+….+n² using Recursion

### C Program to Find Sum of series 1²+2²+3²+….+n² using Standard Formula

```/* C Program to Calculate Sum of series 1²+2²+3²+....+n² */
#include <stdio.h>
int main()
{
int Number, Sum = 0;
printf("\n Please Enter any positive integer \n");
scanf(" %d",&Number);
Sum = (Number * (Number + 1) * (2 * Number + 1 )) / 6;

printf("\n The Sum of Series for %d = %d ",Number, Sum);
}```

The result of above c program; is as follows:

```Please Enter any positive integer
10
The Sum of Series for 10 = 385 ```

### C Program to Find Sum of series 1²+2²+3²+….+n² using For Loop

```#include <stdio.h>
int main()
{
int Number, i, Sum = 0;
printf("\nPlease Enter any positive integer \n");
scanf("%d",&Number);
Sum = (Number * (Number + 1) * (2 * Number + 1 )) / 6;

for(i =1; i<=Number;i++)
{
if (i != Number)
printf("%d^2 + ",i);

else
printf("%d^2 = %d ",i, Sum);
}
}```

The result of above c program; is as follows:

```Please Enter any positive integer
10
1^2 + 2^2 + 3^2 + 4^2 + 5^2 + 6^2 + 7^2 + 8^2 + 9^2 + 10^2 = 385 ```

### C Program to Find Sum of series 1²+2²+3²+….+n² using Function

```#include <stdio.h>
void Sum_Of_Series(int);
int main()
{
int Number;
printf("\n Please Enter any positive integer \n");
scanf("%d",&Number);
Sum_Of_Series(Number);
}
void Sum_Of_Series(int Number)
{
int i, Sum;
Sum = (Number * (Number + 1) * (2 * Number + 1 )) / 6;

for(i =1;i<=Number;i++)
{
if (i != Number)
printf("%d^2 + ",i);
else
printf(" %d^2 = %d ", i, Sum);
}
}```

The result of above c program; is as follows:

```Please Enter any positive integer
5
1^2 + 2^2 + 3^2 + 4^2 +  5^2 = 55 ```

### C Program to Find Sum of series 1²+2²+3²+….+n² using Recursion

```#include <stdio.h>
int Sum_Of_Series(int);
int main()
{
int Number, Sum;
printf("\nPlease Enter any positive integer \n");
scanf("%d",&Number);
Sum=Sum_Of_Series(Number);
printf("\nSum of the Series  = %d",Sum);
}
int Sum_Of_Series(int Number)
{
if(Number == 0)
return 0;

else
return (Number*Number) + Sum_Of_Series(Number-1);
}```

The result of above c program; is as follows:

```Please Enter any positive integer
5
Sum of the Series  = 55```

Categories C