An extremal problem for least common multiples
β Scribed by Melvyn B Nathanson
- Publisher
- Elsevier Science
- Year
- 1987
- Tongue
- English
- Weight
- 482 KB
- Volume
- 64
- Category
- Article
- ISSN
- 0012-365X
No coin nor oath required. For personal study only.
β¦ Synopsis
Let A be a set of natural numbers, and let [A] h denote the set of all least common multiples [al .... , ah] with ai ~ A. If n Β’ [A] h for all sufficiently large integers n, then A is an asymptotic LCM basis of order h. If n Β’ [A] h for infinitely many n t> 1, then A is an asymptotic LCM nonbasis of order h. The nonbasis A is maximal if A t3 {b} is an asymptotic LCM basis of order h for every natural number b Β’ A. In this paper the structure of all maximal asymptotic LCM bases of order h is determined.
π SIMILAR VOLUMES
The Diophantine Problem of Frobenius is to find a formula for the least integer not representable as a nonnegative linear form of positive integers. A reduction formula for the Diophantine Problem of Frobenius is presented. The formula can be applied whenever there are common divisors of the coeffic
It is proved that every graph G with G β₯ 2|G| -5, |G| β₯ 6, and girth at least 5, except the Petersen graph, contains a subdivision of K - 5 , the complete graph on five vertices minus one edge.
## Abstract We introduce the notion of __H__βlinked graphs, where __H__ is a fixed multigraph with vertices __w__~1~,β¦,__w__~m~. A graph __G__ is __H__β__linked__ if for every choice of vertices Ο ~1~,β¦, Ο ~m~ in __G__, there exists a subdivision of __H__ in __G__ such that Ο ~i~ is the branch vertex
Let T be a tree such that there is a proper n-coloring c of the vertices of T which, besides a technical condition, is a k b k a k -free, i.e., T contains no subdivision of a path u 1 , . . . , Then T has O(kn) vertices. (The technical condition requires that T contains no subdivision of a properly