Skip to content

Erdős problem 448

Let τ(n)\tau(n) count the divisors of nn and τ+(n)\tau^+(n) count the number of kk such that nn has a divisor in [2k,2k+1)[2^k, 2^{k+1}). Is it true that, for all ϵ>0\epsilon > 0, τ+(n)<ϵτ(n) \tau^+(n) < \epsilon \cdot \tau(n) for almost all nn?

Sources

Browse retained paths and inspect the exact material available for this Problem.

8 retained statements2415f78e850a

Open selected source

FormalConjectures/ErdosProblems/

448.lean

Retained formal statement6 of 8

Always τ+(n)τ(n)\tau^+(n) \le \tau(n): the occupied dyadic blocks are the image of the divisor set under Nat.log 2, and an image has at most as many elements as its source. This is what makes the ϵ<1\epsilon < 1 comparison in the problem meaningful.

FormalConjectures/ErdosProblems/448.leanErdos448.tauPlus_le_tau1 lineExact file
∀ (n : ℕ), Erdos448.tauPlus nn.divisors.card
TestStatement only, no proof

Search problems.science

Find a Problem, Result, source, or page