(1)由Sn+1+Sn-1=2(Sn+1)变形得,Sn+1-Sn=Sn-Sn-1+2,
∴an+1=an+2,可知数列{an}是从第二项起的等差数列,
又a2-a1=2,所以an=a1+(n-1)×2=2n-1,即数列{an}的通项公式为:an=2n-1;
(2)由(1)得,
=1
anan+1
=1 (2n?1)(2n+1)
(1 2
?1 2n?1
),1 2n+1
∴Tn=
[(1 2
?1 1
)+(1 3
?1 3
)+(1 5
?1 5
)+…+(1 7
?1 2n?1
)]=1 2n+1
,n 2n+1
又∵an+1=2n+1>0,∴Tn≤λan+1?λ≥
恒成立?λ≥(Tn an+1
)maxTn an+1
又
=Tn an+1
=n (2n+1)2
=n 4n2+4n+1
,1 4n+
+41 n
∵y=4n+
+4在[1,+∞)上单调递增,1 n
∴n=1时,ymin=9,(
)max=Tn an+1
1 9
所以λ≥
.1 9