解答:a1=1,ana(n+1)=2^n∴ a1*a2=2^1∴ a2=2又 ana(n+1)=2^n∴ a(n-1)*a(n)=2^(n+1) n≥2∴ a(n+1)/a(n-1)=2即 a1,a3,a5,a7,.......成等比数列,公比是2 a2,a4,a6,a8,.......成等比数列,公比是2∴ a9=a1*2^4=16 a10=a2*2^4=32∴ a9+a10=48