对于该题q肯定不为1那么Sn=a1*(1-q^n)/(1-q)因为S4/S8=1/17所以[a1*(1-q^4)/(1-q)]/[a1*(1-q^8)/(1-q)]=1/17即q^4=16那么S8/S16=[a1*(1-q^8)/(1-q)]/[a1*(1-q^16)/(1-q)]=1/(1+q^8)=1/(1+16^2)=1/257...