Erdős problem 418
Are there infinitely many integers not of the form ?
Sources
FormalConjectures/ErdosProblems/
418.lean
Retained formal statement
It is open whether the set of non-cototients has positive density.
True ↔ ∃ S, ∃ (_ : S.HasPosDensity), S ⊆ {x | ∃ n, n - n.totient = x}ᶜOpenStatement only, no proof