#include <stdio.h>
#include <stdlib.h>
#include <math.h>
int main(int argc, char *argv[])
{
double sum=0;
int n,k;
printf("请输入正整数n:");
scanf("%d",&n);
for(k=1;k<=n;k++){
sum=sum+k/(2*k-1);
}
printf("数列的和:%.20lf\n",sum);
return 0;
}
请输入正整数n:100
数列的和:51.64217109465084832000