(1)当n=1时,a2=S1+1=a1+1=2;
当n≥2时,Sn+1=an+1,Sn-1+1=an,兩式相减得,an+1=2an,
又a2=2a1,
∴{an}是首项为1,公比为2的等比数列,
∴an=2n-1.
(2)由(1)知an=2n-1,
∴bn=
=n 4an
=n 4?2n?1
,n 2n+1
∴Tn=
+1 22
+2 23
+…+3 24
,n 2n+1
Tn=1 2
+1 23
+2 24
+…+3 25
+n?1 2n+1
,n 2n+2
两式相减得,
Tn=1 2
+1 22
+1 23
+…+1 24
?1 2n+1
n 2n+2
=
-
(1?1 22
)1 2n 1?
1 2
=n 2n+2
1 2