Erdős Problem #652
The statement as posed is true, and a proof exists.
What the community database records, not our verdict. erdosproblems.com no longer shows statuses (why).
The positive constants \(a\) such that, for all sufficiently large \(n\), some set of \(n\) points has at least \(k\) points determining fewer than \(a\sqrt n\) distances to its other points. Counting these points expresses \(R(x_k)<a\sqrt n\) without choosing an ordering.
The infimum of the admissible positive constants for the \(k\)th smallest distance count. An infimum is used because a least constant need not exist for a strict inequality.
Attempts
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