Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4647523 | Discrete Mathematics | 2013 | 6 Pages |
Abstract
Let N0 be the set of non-negative integers, and let P(n,l) denote the set of all weak compositions of n with l parts, i.e., P(n,l)={(x1,x2,â¦,xl)âN0l:x1+x2+â¯+xl=n}. For any element u=(u1,u2,â¦,ul)âP(n,l), denote its ith-coordinate by u(i), i.e., u(i)=ui. A family AâP(n,l) is said to be t-intersecting if |{i:u(i)=v(i)}|â¥t for all u,vâA. We prove that given any positive integers l,t with lâ¥t+2, there exists a constant n0(l,t) depending only on l and t, such that for all nâ¥n0(l,t), if AâP(n,l) is t-intersecting then |A|â¤n+lâtâ1lâtâ1. Moreover, the equality holds if and only if A={uâP(n,l):u(j)=0for alljâT} for some t-set T of {1,2,â¦,l}.
Keywords
Related Topics
Physical Sciences and Engineering
Mathematics
Discrete Mathematics and Combinatorics
Authors
Cheng Yeaw Ku, Kok Bin Wong,