#include<stdio.h>int main(){double sum=0.0,a=1.0;int i,j,n;scanf("%d",&n);for(i=1;i<=n;i++){for(j=i;j<=(2i-1);j++)a=a(1.0/j);sum+=a;a=1.0;}printf("%lf",sum);return 0;}应该是这样,如果有帮助请采纳一下,谢谢