(1)易得1/an^2=1/a(n+1)^2-4
所以数列{1/an^2}为首项1/a1^2=1,公差为4的等差数列
1/an^2=4n-3
an=1/√(4n-3)
(2)根据题意,有Tn+(4n-3)=Tn(4n+1)+(4n-3)(4n+1)
4n*Tn=(4n-3)(-4n)
即Tn=3-4n
所以{bn}:-1,-4,-4,-4,-4,……
故不存在b1使{bn}为等差数列
(1)易得1/an^2=1/a(n+1)^2-4
所以数列{1/an^2}为首项1/a1^2=1,公差为4的等差数列
1/an^2=4n-3
an=1/√(4n-3)
(2)根据题意,有Tn+(4n-3)=Tn(4n+1)+(4n-3)(4n+1)
4n*Tn=(4n-3)(-4n)
即Tn=3-4n
所以{bn}:-1,-4,-4,-4,-4,……
故不存在b1使{bn}为等差数列