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Erdős problem 1192

Does there exist, for all r≥2r\geq 2, a basis AA of order rr (so that fr(n)>0f_r(n)>0 for all large nn) such that ∑n≤xfr(n)2≪x\sum_{n\leq x}f_r(n)^2 \ll x for all xx?

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The source's own material, retained exactly.

7 retained statements36c6d0fef71a

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FormalConjectures/ErdosProblems/

1192.lean

Retained formal statement7 of 7

Ruzsa [Ru90] proved that the answer is yes for r=2r=2.

FormalConjectures/ErdosProblems/1192.leanErdos1192.erdos_1192.variants.ruzsa3 linesExact file
∃ A,  (∀ᶠ (n : ℕ) in Filter.atTop, Erdos1192.f_r A 2 n > 0) ∧    (fun x => ∑ n ∈ Finset.range (x + 1), ↑(Erdos1192.f_r A 2 n) ^ 2) =O[Filter.atTop] fun x => ↑x
SolvedStatement only, no proof