Problems / number-theory
number-theory / Analytic number theory; smooth numbers and largest prime factors
Erdos Problem #371: do the integers with P(n) < P(n+1) have density 1/2? (Erdos-Pomerance joint independence of largest prime factors)
Theorem 1.1: for fixed a,b∈(0,1), X1#{2≤n≤X:P+(n)≤na,P+(n+1)≤nb}→ρ(1/a)ρ(1/b), unconditionally and at every large scale. Corollary 1.2: P+(n)<P+(n+1) and the reverse ordering each have natural density 1/2. Inclusion-exclusion also gives the Erdos-Pomerance upper-tail independence statement. It gives no rate and no uniformity in a,b (unlike the almost-all-scales quantitative law of Tao-Teravainen 2026), and says nothing about three consecutive integers (Erdos #372 and Balog's density 1/6 conjecture).