OAI/NumberTheory/EgyptianFractions/SmallPrimeDivisors.lean
3 declarations, 0 contain sorry, 0 declared as axioms
- theorem
OAI.Problem337.divisor_card_small_primes_boundline 9Source documentation
A number with only small prime factors has few divisors once its logarithm is bounded.
theorem divisor_card_small_primes_bound (z W : ℝ) {n : ℕ} (hn : n ≠ 0) (hz : 0 ≤ z) (hnW : Real.log (n : ℝ) ≤ W) (hsmall : ∀ p ∈ n.primeFactors, (p : ℝ) ≤ z) : (n.divisors.card : ℝ) ≤ Real.exp (z * Real.log (1 + W / Real.log 2)) := by … - theorem
OAI.Problem337.truncatedDivisorCount_pointwise_exp_boundline 55Source documentation
Split the factor list at z and combine the small- and large-prime estimates.
theorem truncatedDivisorCount_pointwise_exp_bound (X z W : ℝ) {n : ℕ} (hn : n ≠ 0) (hX : 1 < X) (hz : 1 < z) (hXW : Real.log X ≤ W) (hnW : Real.log (n : ℝ) ≤ W) : (truncatedDivisorCount X n : ℝ) ≤ Real.exp (z * Real.log (1 + W / Real.log 2) + (1 + Real.log (W / Real.log X)) * Real.log X / Real.log z) := by …Mentions: OAI.Problem337.truncatedDivisorCount
- theorem
OAI.Problem337.truncatedDivisorCount_pointwise_log_boundline 116Source documentation
Logarithmic version of the elementary small/large-prime split.
theorem truncatedDivisorCount_pointwise_log_bound (X z W : ℝ) {n : ℕ} (hn : n ≠ 0) (hX : 1 < X) (hz : 1 < z) (hXW : Real.log X ≤ W) (hnW : Real.log (n : ℝ) ≤ W) : Real.log (truncatedDivisorCount X n : ℝ) ≤ z * Real.log (1 + W / Real.log 2) + (1 + Real.log (W / Real.log X)) * Real.log X / Real.log z := by …Mentions: OAI.Problem337.truncatedDivisorCount