In this tutorial learn **how you can write a c program to ****evaluate the series S= 1+ 2×1 +3×2 +….+ nxn-1. where n is given by user.**

We are using for loop for this tutorial.

**C programming** is a powerful **general-purpose programming language**. It can be used to develop software like operating systems, databases, compilers, etc.

## Write a Program to Evaluate the Series S= 1+ 2×1 +3×2 +….+ nxn-1

Here is the code to evaluate the series S= 1+ 2×1 +3×2 +….+ nxn-1. where n is given by user. in C programming.

#include <stdio.h> //WAP to evaluate the series S= 1+ 2x1 +3x2 +….+ nxn-1. where n is given by user.

int main()

{

int n, i, sum = 1;

printf("Enter n terms for series:");

scanf("%d", &n);

for (i = 1; i <= n; i++)

{

sum = sum + i * (i - 1);

}

printf("sum of the series is %d.", sum);

return 0;

}

## Test Live At Jdoodle

## Conclusion

This is **how you can ****evaluate the series S= 1+ 2×1 +3×2 +….+ nxn-1. where n is given by user. in c programming.** Comment below if you like our tutorial.