解:(1)由Sn=2n^2+n可得,当n=1时,a1=s1=3
当n≥2时,an=sn-sn-1=2n^2+n-2(n-1)^2-(n-1)=4n-1
而n=1,a1=4-1=3适合上式,
故an=4n-1,
又∵an=4log2bn+3=4n-1
∴bn=2^n−1
(2)由(Ⅰ)知,anbn=(4n−1)•2^n−1
Tn=3×2^0+7×2+…+(4n−1)•2^n−1
2Tn=3×2+7×2^2+…+(4n-5)•2^n-1+(4n-1)•2^n
∴Tn=(4n−1)•2^n−[3+4(2+2^2+…+2^n−1)]
=(4n-1)•2^n−[3+4•2(1−2n−1)/1−2]
=(4n-1)•2^n-[3+4(2^n-2)]=(4n-5)•2^n+5