English

An identity involving the least common multiple of binomial coefficients and its application

Number Theory 2009-06-15 v2

Abstract

In this paper, we prove the identity \lcm{(k0),(k1),>...,(kk)}=\lcm(1,2,...,k,k+1)k+1(kN).\lcm\{\binom{k}{0}, \binom{k}{1}, >..., \binom{k}{k}\} = \frac{\lcm(1, 2, ..., k, k + 1)}{k + 1} (\forall k \in \mathbb{N}) . As an application, we give an easily proof of the well-known nontrivial lower bound \lcm(1,2,...,k)2k1\lcm(1, 2, ..., k) \geq 2^{k - 1} (k1)(\forall k \geq 1).

Keywords

Cite

@article{arxiv.0906.2295,
  title  = {An identity involving the least common multiple of binomial coefficients and its application},
  author = {Bakir Farhi},
  journal= {arXiv preprint arXiv:0906.2295},
  year   = {2009}
}

Comments

5 pages. To appear in American Mathematical Monthly