2^99-2^98+2^97-2^96+2^95-2^94+……+2^3-2^2+2=(2^99-2^98)+(2^97-2^96)+(2^95-2^94)+……+(2^3-2^2)+2=(2^98+2^96+2^94+……+2^2+1)+1括弧里是一个等比数列。(2^98+2^96+2^94+……+2^2+1)+1=(2^100-1)/3≈1.239e63
