这些数的规律是后一个数的两倍就是它前一个数,如:1/4=1/8+1/8,1/4+1/4=1/2,1/256=1/512+1/512
1/2+1/4+1/8+……+1/512
=(1/2+1/4+1/8+……+1/512+1/512)-1/512
= 511/512
这些数的规律是后一个数的两倍就是它前一个数,如:1/4=1/8+1/8,1/4+1/4=1/2,1/256=1/512+1/512
1/2+1/4+1/8+……+1/512
=(1/2+1/4+1/8+……+1/512+1/512)-1/512
= 511/512