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Erdős problem 1192

Does there exist, for all r2r\geq 2, a basis AA of order rr (so that fr(n)>0f_r(n)>0 for all large nn) such that nxfr(n)2x\sum_{n\leq x}f_r(n)^2 \ll x for all xx?

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7 retained statements2415f78e850a

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FormalConjectures/ErdosProblems/

1192.lean

Retained formal statement6 of 7

Erdős and Rényi proved by the probabilistic method that there exists a set AA such that nxfr(n)2x\sum_{n\leq x}f_r(n)^2 \ll x and A[1,x]x1/r\lvert A\cap [1,x]\rvert\gg x^{1/r} for all xx.

FormalConjectures/ErdosProblems/1192.leanErdos1192.erdos_1192.variants.renyi4 linesExact file
r ≥ 2,A,    ((fun x => ∑ nFinset.range (x + 1), ↑(Erdos1192.f_r A r n) ^ 2) =O[Filter.atTop] fun x => ↑x) ∧      (fun x => ↑x ^ (1 / ↑r)) =O[Filter.atTop] fun x => ↑(Nat.count A x)
SolvedStatement only, no proof

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