(I)设公差为d,由已知得:
,
S4=14
a32=a1a7
即
,
4a1+
d=144×3 2
(a1+2d)2=a1(a1+6d)
解得:d=1或d=0(舍去),
∴a1=2,
故an=2+(n-1)=n+1;
(II)∵
=1
anan+1
=1 (n+1)(n+2)
-1 n+1
,1 n+2
∴Tn=
-1 2
+1 3
-1 3
+…+1 4
-1 n+1
=1 n+2
-1 2
=1 n+2
,n 2(n+2)
∵Tn≤λan+1对?n∈N*恒成立,即
≤λ(n+2),λ≥n 2(n+2)
?n∈N*恒成立,n 2(n+2)2
又
=n 2(n+2)2
≤1 2(n+
+4)4 n
=1 2(4+4)
,1 16
∴λ的最小值为
.1 16