奇特的分数数列

#include<stdio.h>
#include<stdlib.h>
#include<math.h>

int main()
{
int m = 2,n = 1,i=0,k;
double s=0;
while(i<20){
s += (double)m/n;
i++;
k = m;
m = m + n;
n = k;
}
printf("%.6lf\n",s);
return 0;
}