S=1+2的负一次方+2的负二次方+2的负三次方+……+2的负2010次方
=1+1/2+1/2^2+1/2^3+……+1/2^2010
以1/2为公比的等比数列
=1*(1-(1/2)^2011)/(1-1/2)
=2-(1/2)^2010