看到你問過一個類似的題目,三個連續(xù)自然數(shù)相乘的倒數(shù),此題類似,考慮通式：
（2n+3)/[n(n+1)(n+2)(n+3)]=(n+n+3)/[n(n+1)(n+2)(n+3)]
=1/[(n+1)(n+2)(n+3)]+1/[n(n+1)(n+2)]
已經(jīng)變化成兩個完全相似的題目之和,你可以自己練練手了.