已知等比数列,a(5)×a(2n-5)=2的2n次方an=a1q∧（n-1);a5=a1q∧4a(2n-5)=a1q∧2n-6a5*a(2n-5)=a1²q∧2n-2=2∧2n,∴ a1=2,q=2log2a1+log2a3+...+log2a(2n-1)=1+3+5+...+2n-1=(2n-1+1)*(n-1)/2=n(n-1)...