根据题意有：(an+1)/an=2[（n+1)/n]^2 an=(an/an-1)*(an-1/an-2).*a2/a1===2^(n-1)*[n^2/(n-1)^2].*(2^2/1^2)===2^(n-1)*n^2an=2^(n-1)*n^2an/n=2^(n-1)*n 令bn=an/n 所以有bn=n*2^(n-1)sn=b1+b2+b3+.+bn=1*2^0+2*2^...