Extremal sets with distinct least common multiples – mathoverflow.net

Let $p_1, p_2, p_3, p_4, p_5 ... = 2, 3, 5, 7, 11, ...$ be the prime numbers in increasing order. Let k > 5 and $A_k = {1, 4, 5, 6, 7, 9, 11, p_6, ..., p_k}$. In $A_k$ all least common multiples ...