设n是正整数,n-分拆是指将n表为一个或多个正整数的和的形式.两个和式若仅有加数顺序的差异则视为相同的分拆.称和式中的每个加数为这个n-分拆的一个部分.以Pr(n)表示部分数为r的n分拆的个数.本文研究了部分数为5的n-分拆,得到了P5(n)的一个简易的计算公式.
A partition of a positive integer is a way of writing as a sum of one or more positive integers. Two sums which only differ in the order of their summands are considered to be the same partition. A summand in a partition is also called a part. The number of partitions of into exactly parts is denoted by. In this paper, we study the partitions of into exactly 5 parts, and obtain a counting formula.