The series 1+3+5+..+n, is a series of odd number. We need to write a program to display this series as well as find the sum upto n^th number. The n will be inserted by the user. The program has been compiled and executed under DEV c++.

CODE:

#include
void main()
{
	int i,n,sum=1;
	printf("Enter any number n:");
	scanf("%d",&n);
	printf("\n1 ");
	for(i=3;i<=n;i++){
		printf("+ %d ",i);
		sum=sum+i;
		i++;
	}
	printf("\nSum is: %d", sum);
}

OUTPUT:

Explanation: The i is incremented twice in the above program. First in the for loop itself and second inside the loop. There are multiple ways to do this. I choose to do it this way.