Erdős problem 1072
Erdős, Hardy, and Subbarao [HaSu02], believed that the number of for which is .
Sources
FormalConjectures/ErdosProblems/
1072.lean
Retained formal statement
Erdős, Hardy, and Subbarao [HaSu02], believed that the number of for which is .
[HaSu02] Hardy, G. E. and Subbarao, M. V., _A modified problem of Pillai and some related questions._ Amer. Math. Monthly (2002), 554--559.
(fun x => ↑({p | Nat.Prime p ∧ Erdos1072.f p = p - 1} ∩ Set.Icc 0 x).ncard) =o[Filter.atTop] fun x => ↑x / Real.log ↑xOpenStatement only, no proof