8/1*5+8/5*9+8/9*13+8/13*17
=2*(4/1*5+4/5*9+4/9*13+4/13*17)
=2*(1-1/5+1/5-1/9+1/9-1/13+1/13-1/17)
=2*(1-1/17)
=32/17