15.The sum of first Nth natural number using recursion

 #include<stdio.h>

int natural(int x);

int main(){

    int num;

    printf("Enter the Nth number :");

    scanf("%d",&num);

    printf("\nThe sum of first natural number till %d is :%d",num,natural(num));

    return 0;

}

    int natural(int x)

    {  

        if(x==1)

        return x;

        else

        return x+natural(x-1);

    }