Java求一个分数数列的前20项之和的实现代码

public class test20 {  public static void main(String[] args) {    float fm = 1f;    float fz = 1f;    float temp;    float sum = 0f;    for (int i=0;i<20;i++){       temp = fm;       fm = fz;       fz = fz + temp;       sum += fz/fm;       //System.out.println(sum);    }    System.out.println(sum);  }}