Erdős problem 329
Erdős Problem 329. Let A ⊆ ℕ be a Sidon set. How large can lim sup_{N → ∞} |A ∩ {1,…,N}| / N^{1/2} be?
Sources
FormalConjectures/ErdosProblems/
329.lean
Retained formal statement
Erdős and Turán [ErTu41] proved the upper bound of 1.
[ErTu41] Erdős, P. and Turán, P., On a problem of Sidon in additive number theory, and on some related problems. J. London Math. Soc. (1941), 212-215.
∀ (A : Set ℕ), IsSidon A → Erdos329.sidonUpperDensity A ≤ 1SolvedStatement only, no proof