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Erdős problem 647

Let τ(n)\tau(n) count the number of divisors of nn. Is there some n>24n > 24 such that max⁡m<n(m+τ(m))≤n+2? \max_{m < n}(m + \tau(m)) \leq n + 2?

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The source's own material, retained exactly.

4 retained statements36c6d0fef71a

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FormalConjectures/ErdosProblems/

647.lean

Retained formal statement2 of 4

Erdős says it 'seems certain' that for every kk there are infinitely many nn for which max⁡n−k<m<n(m+τ(m))≤n+2. \max_{n−k < m < n}(m + \tau(m)) ≤ n + 2.

FormalConjectures/ErdosProblems/647.leanErdos647.erdos_647.variants.infinite1 lineExact file
sorry ↔ ∀ (k : ℕ), {n | ⨆ m, ↑m + (ArithmeticFunction.sigma 0) ↑m ≤ n + 2}.Infinite
OpenStatement only, no proof