Sum of the series S=1+(1+2)+(1+2+3)+(1+2+3+4)+….+(1+2+3+…+n) where the value of ‘n’ is given by the user.

#include<stdio.h>

int main(){

int n,sum,sum1=0,i,j;

printf("Please enter an integer n=");

scanf("%d",&n);

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

sum=0;

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

sum=sum+j;

sum1=sum1+sum;

}

printf("The sum of the series=%d\n",sum1);

return 0;

}