a(n)*a(n+1)=2^n,令n=1,可得a(2)=2.另有a(n+1)*a(n+2)=2^(n+1),则a(n+2)/a(n)=2.于是a(2n)=2^(n-1)*a(2)=2^n,a(2n+1)=2^n*a(1)=2^n.则a(9)=2^4=16,a(10)=2^5=32,于是a(9)+a(10)=48