Qi Qi WU
Let P(n, k) be the number of unordered partitions of an integer n into k parts where each part ≥1, set by master Euler (1707-1783). It is one of most important numbers in Combinatorics, Graph theory and Number theory.However, it is rather difficult to find the values of P(n, k) and to construct a large table of P(n, k). In this paper, from this formula P(n, k) = P(n - 1, k - 1) + P(n - k, k) we define the "number of left shoulder" of P(n, k) and the "acute number" of P(n, k), by which we get at the "law of left shoulder" to find P(n, k) (First law), also the "law of oblique line" to find P(n, k) (Second law) on the basis of some important theorems of the paper Wu Qiqi [5]. By using these laws we obtaine an ioteresting principle for constructing a large table of P(n, k). For the sake of convenience, we use the only first law to design the proceeding of calculator, by which we can quickly construct an arbitrary large table of P(n, k).