````````````````1/1`````````````1/2```1/2`````````1/3```1/6```1/3``````1/4``1/12``1/12``1/4````1/51/20``1/30``1/20`1/5``1/61/30`1/60`1/60`1/30`1/61/71/421/1051/1401/1051/421/7把数阵依金字塔式整齐写好就可以发现两边的数的既定的,第n行第1个数就是a(n,1)=1/n然后依次往内填充在中线以左的数a(n,m)是由a(n-1,m-1)-a(n,m-1)计算出所以a(10,3)=a(9,2)-a(10,2)=[a(8,1)-a(9,1)]-[a(9,1)-a(10,1)]=1/8-1/9-1/9+1/10=1/360