原式= 1 + (1/2+1/3) + (1/4+1/5+1/6+1/7) +(1/8+1/9+1/10+1/11+ ...+1/15) ...< 1 + (1/2+1/2) + (1/4+1/4+1/4+1/4) + ...=1+1+1+1+1+1+1+1+1+1/512*512+1/1024*1024=11所以：原式