Erdős problem 971
Let p(a, d) be the least prime congruent to a (mod d). Does there exist a constant c > 0 such that for all large d, p(a, d) > (1 + c) * φ(d) * log d for ≫ φ(d) many values of a?
Sources
FormalConjectures/ErdosProblems/
971.lean
Retained formal statement
Erdős [Er49c] proved that for any ε > 0 we have p(a, d) < ε * φ(d) * log d for ≫_ε φ(d) many values of a (for all large d).
[Er49c] Erdős, P., _On some applications of Brun's method_. Acta Univ. Szeged. Sect. Sci. Math. (1949), 57--63.
∀ ε > 0, ∃ C > 0, ∀ᶠ (d : ℕ) in Filter.atTop, C * ↑d.totient ≤ ↑{a ∈ Finset.Iio d | a.Coprime d ∧ ↑(Erdos971.leastCongruentPrime a d) < ε * ↑d.totient * Real.log ↑d}.cardSolvedStatement only, no proof