关键词： 严格排列, k元组合, 容斥原理

Abstract:

We have calculated the k combination f(2m,k)=f(2(m－1),k)+f(2(m－1),k－1)+f(2(m－2),k－1) of asynchronously appearing i and i+1,j and j+3,where m∈{1,2,3…},i∈{1,2,…,2m－1},j∈{1,3,5,…,2m－3},in the set S={1,2,…,2m}.Making use of inclusion and exclusion principle,we have sloved the question that they are disconnectly i element's and i+1 element's n permutation p(n)=n!+∑〖DD(〗n－1〖〗i=1〖DD)〗((－1) if (2(n－1),i)(n－i)!),where n∈{4,5,6,…},i∈{1,2,…,n－1},in the set N={1,2,3,…,n}.

Key words: strict permutation, k combination, inclusion and exclusion