permutation without repetition

This paper deals with the problems of enumeration of repeated permutations in which no element may repeated three times consecutioely.

讨论了r元的n重复排列，其中有s个元的每一个不许3个相邻的问题，作为应用，又讨论了3×n广义棋盘的2染色问题。

A sort of 3-element permutation with repetitions allowed is studied,and a recurrence relation in general condition is found.

研究一类特殊的可重复排列性质,建立了一般情形下求这类排列数的递推公式,导出了一些特殊情形下的具体计算公式。

We set up a count -model of r-repeatable cyclic permutation of n-set, define the discrete function and S (r, n), and discuss their properties.

首先给出n元集每个元至少出现 1次的r -可重复圆排列数er(n)的计数模型 ,进而定义带符号的可重复圆排列数s(r ,n) =(- 1) r-ner(n) ,讨论了er(n)与s(r ,n)的性质 ,从而造出s(r ,n)表 。