今日来一道计算题~
题目要求:
编写一个函数(SeriesSum),该函数返回到第n项(参数)的后续序列的和
举个栗子:
- SeriesSum(1) => 1 = "1"
- SeriesSum(2) => 1 + 1/4 = "1.25"
- SeriesSum(5) => 1 + 1/4 + 1/7 + 1/10 + 1/13 = "1.57"
答案:
- def series_sum(n):
- num = 1
- result = 0
- for i in range(n):
- result += 1 / num
- num += 3
- return '%.2f' % result