Fibonacci series in C non recursive

Objective : To print given numbers of Fibonacci series. (1,1,2,3,5.....) non recursively.
Programming Logic: Its easy to print the above Fibonacci series in C. the number is always sum of previous 2 terms. This series starts with numbers 1,1. so next term is 1+1=2. Then next term is 1+2=3 and so on.
(It may be noted that series 1,3,4,7,11,18.... is also a Fibonacci series, but it starts with 1,3 )

Code :

#include<stdio.h>
int main()
{
    int k;
    printf("\n enter number of terms to print=");
    scanf("%d",&k);
    fic(k);
    return(0);
}
void fic(int x)// x are number of terms to print
{
    int a,b,sum,i;
    a=b=1;
    printf("1,1,",sum);//first 2  terms
    for(i=0;i<x-2;i++)
    {
        sum=a+b;
        printf("%d,",sum);
        a=b;
        b=sum;    
    }
}

It may be noted that using a non recursive way to calculate Fibonacci series in C provides faster calculations as compared with recursive method. As recursive program have a large overhead of function calls. Also the recursive way is very unoptimised since it doesn't uses the last 2 values that have been calculated already..