Erdős problem 955 · problems.science

If $A\subset \mathbb{N}$ has density $0$ then $s^{-1}(A)$ must also have density $0$ .

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12 retained statements2415f78e850a

FormalConjectures/ErdosProblems/

955.lean

Retained formal statement5 of 12

It is possible for $s(A)$ to have positive density even if $A$ has zero density (for example taking $A$ to be the product of two distinct primes).

FormalConjectures/ErdosProblems/955.leanErdos955.erdos_955.variants.positive_density1 lineExact file

1∃ A, A.HasDensity 0 ∧ ∃ d > 0, (Erdos955.s '' A).HasDensity d

SolvedStatement only, no proof