(1)∵6Sn=1-2an,
∴当n=1时,6a1=1-2a1,解得,a1=
,1 8
当n≥2时,6(Sn-Sn-1)=(1-2an)-(1-2an-1),
即an=
an-1,1 4
∴数列{an}是以
为首项,1 8
为公比的等比数列,1 4
∴an=
?(1 8
)n-1=1 4
?(1 2
)n,1 4
(2)∵log
1 2
?(1 2
)n=2n+1,1 4
故bn=(-1)n-1?
4(n+1)
log
an?log1 2
an+1
1 2
=(-1)n-1?
,4(n+1) (2n+1)(2n+3)
∵当n为偶数时,
bn-1+bn=
-4n (2n?1)(2n+1)
4(n+1) (2n+1)(2n+3)
=
=4 (2n?1)(2n+3)
-1 2n?1
,1 2n+3
故Tn=b1+b2+b3+b4+…+bn-1+bn
=(b1+b2)+(b3+b4)+…+(bn-1+bn)
=
-1 3
+1 7
-1 7
+…+1 11
-1 2n?1
1 2n+3
=
-1 3
=1 2n+3
,2n 3(2n+3)
当n为奇数时,
Tn=b1+b2+b3+b4+…+bn-2+bn-1+bn
=(b1+b2)+(b3+b4)+…+(bn-2+bn-1)+bn
=
-1 3
+1 7
-1 7
+…+1 11
-1 2n?3
+1 2n+1
4(n+1) (2n+1)(2n+3)
=
-1 3
+1 2n+1
4(n+1) (2n+1)(2n+3)
=
.2(n+3) 3(2n+3)
故Tn=
n∈N*.
,n为偶数2n 3(2n+3)
,n为奇数2(n+3) 3(2n+3)