Problem A. 664. (February 2016)
A. 664. Let \(\displaystyle a_1<a_2<\ldots<a_n\) be an arithmetic progression of positive integers. Prove that \(\displaystyle [a_1,a_2,\ldots,a_n] \ge [1,2,\ldots,n]\). (The symbol \(\displaystyle [\ldots]\) stands for the least common multiple.)
Deadline expired on 10 March 2016.