0.064=0.4^30.16=0.4^20.4=0.4^11=0.4^0()=0.4^(-1)=2.56.25=0.4^(-2)规律：指数依次减10.064 ,0.16 ,0.4 ,1,（2.5 ）,6,250.4375()=0.4375*2=0.875()=0.875*2=1.751.75*2=3.53.5*2=77*2=14规律：依次乘20.4375 （0....