谢谢
还有呢?
Sn=n(31-2n+33)/2=32n-n^2求数列{bn}的前n项和Tnbn=|an|-2n+33 >0==>n≤16n≤16时,Tn=Sn=32n-n^2n≥17时,Tn=S16+|a17|+...+|an| =256+(1-33+2n)(n-16)/2=256+(n-16)^2=n^2-32n+512∴Tn= 32n-n^2 (n≤16) n^2-32n+512 (n≥17)