ErdosProblems · research solved · AMS 11

hardknown result, no worker yet

Erdős Problem 277

Theorem 277 · Erdős

Is it true that, for every cc, there exists an nn such that σ(n)>cn\sigma(n)>cn but there is no covering system whose moduli all divide nn?

This was answered affirmatively by Haight [Ha79].

Formal statement · Lean 4.lean
theorem erdos_277 :
   answer(True) ↔ ∀ c : ℝ, ∃ n : ℕ, (σ 1 n : ℝ) > c * n ∧
      ∀ (m : StrictCoveringSystem ℤ), ∃ i, (n : ℤ) ∉ m.moduli i := by
  sorry

Proof. sorry

Nobody has tried yet.

Reference ↗ · Lean source ↗