若x不是等于1的有理数,我们把1/（1-X）称为X的差倒数,如2的差倒数是1/（1-2）=-1,

x2 = 1/(1-x1)
x3 = 1/(1-x2) = 1/(1-1/(1-x1)) = -(1-x1)/(x1)
x4 = 1/(1-x3) = x1/[x1 +1-x1] =x1
可见这就是一个循环,你多试几次就知道了
2014= 671*3 +1
x2014=x1