The board / number theory / #268
Erdős Problem #268
PROVED LEANdatabase updated 2026-04-13
The statement as posed is true, and a proof exists. A solution has also been checked by machine, in Lean.
What the community database records, not our verdict. erdosproblems.com no longer shows statuses (why).
Let `X` be the set of points in `Fin d → ℝ` of the shape `fun i : Fin d => ∑' n : A, (1 : ℝ) / (n + i)` for some infinite subset `A ⊆ ℕ` such that `1 / n` is summable over `A`. `X` has nonempty interior. This is proved in [KoTa24]. -
Statement as formalized in Formal Conjectures (Google DeepMind, Apache-2.0) · their label: research solved. The authoritative wording is on erdosproblems.com/268.Prizenone
Topicsnumber theory
Statement in LeanFormal Conjectures
Solution in Leanyes
Original pageerdosproblems.com/268
Attempts
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