还是用列表来解决

解题思路:

注意事项:

参考代码:

n = int(input())

fenzi = [2]

fenmu = [1]

for i in range(1,n+1):

    fenzi.append(fenzi[i-1]+fenmu[i-1])

    fenmu.append(fenzi[i-1])

sum = 0

for i in range(n):

    sum = sum + (fenzi[i]/fenmu[i])

print('%.2f'%sum)