T4=a1a2a3a4=1357=1052an=Tn/T(n-1)=n^2/(n-1)^2 (n>=2)a1=T1=1所以,an=n^2/(n-1)^2(n>=2) 1 (n=1)第九层显然2块,那么第八层就是(2+1)2-2=4块...