wap to find sum of first n terms using recursive function

/*wap to find sum of first n terms using recursive function*/

#include<stdio.h>
#include<conio.h>

int addition(int sum);
void main()
{
 int n,sum;
 clrscr();
 printf("enter value of n:");
 scanf("%d",&n);
 sum=addition(n);
 printf("sum of first %d numbers:%d",n,sum);
 getch();
}

int addition(int n)
{
 int sum=0;
 if(n==1)
        { return(1);          }
 else
        { sum=n+addition(n-1);
   return(sum);        }
}