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Research notes on every problem, and a library of the papers behind them. Built from the open erdos repository.

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Claim. P. Pollack and L. Troupe, Sums of proper divisors follow the Erdős--Kac law, Proc. Amer. Math. Soc. 151 (2023), no. 3, 977--988, Theorem 1: for each fixed real uu, as x→∞x\to\infty,

1x#{1<n≤x:ω(s(n))−log⁡log⁡x≤ulog⁡log⁡x}→12π∫−∞ue−t2/2 dt\frac1x\#\{1<n\le x:\omega(s(n))-\log\log x\le u\sqrt{\log\log x}\} \to\frac1{\sqrt{2\pi}}\int_{-\infty}^{u}e^{-t^2/2}\,dt

(card).

Derived as the card states, not stated as a theorem in the paper: for every h(m)→∞h(m)\to\infty the target {m≥3:∣ω(m)−log⁡log⁡m∣>h(m)(log⁡log⁡m)1/2}\{m\ge3:|\omega(m)-\log\log m|>h(m)(\log\log m)^{1/2}\} has density zero by the classical Erdős--Kac theorem, and Theorem 1, with log⁡log⁡x\log\log x replaced by log⁡log⁡s(n)\log\log s(n) for all but o(x)o(x) of the n≤xn\le x, gives it a density-zero preimage, the assertion of Problem 955 for that target.

Covers. For every h(m)→∞h(m)\to\infty, the target {m≥3:∣ω(m)−log⁡log⁡m∣>h(m)(log⁡log⁡m)1/2}\{m\ge3:|\omega(m)-\log\log m|>h(m)(\log\log m)^{1/2}\}; the general assertion stays open.

Depends on. No page of this wiki.

Acceptance. Refereed: Proceedings of the American Mathematical Society, a journal. The site's commentary does not credit the result, and the site labels the problem OPEN, so no curator acceptance is listed.