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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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Statement

With the Section 1 constants Λr\Lambda_r, λr\lambda_r, μr\mu_r (the infimum over sequences of lim sup⁡nnMnr(a)\limsup_nnM_n^r(a), the supremum of lim inf⁡nnmnr(a)\liminf_nnm_n^r(a) and the infimum of lim sup⁡nMnr(a)/mnr(a)\limsup_nM_n^r(a)/m_n^r(a), where Mnr(a)M_n^r(a) and mnr(a)m_n^r(a) are the largest and smallest sums of rr consecutive intervals cut by a1,…,ana_1,\ldots,a_n on the circle of circumference 11), Section 6 (p. 17) says that the bounds (3.3), (4.3) and (5.7) are "probably not best possible if r≥2r\ge2" and conjectures that the expressions

r(Λr−1),r(1−λr),r(μr−1)r(\Lambda_r-1),\qquad r(1-\lambda_r),\qquad r(\mu_r-1)

"tend to infinity if r→∞r\to\infty". The introduction (p. 14) states the third part alone, as the conjecture that r(μr−1)r(\mu_r-1) is unbounded, and adds that the "just distributions" theorem of van Aardenne-Ehrenfest (Proc. 48 (1945), 266--271 = Indag. Math. 7 (1946), 71--76) would follow from it. The site's Problem 1221 reproduces the Section 6 wording.

Source. N. G. de Bruijn and P. Erdős, Sequences of points on a circle, Proc. 52 (1949), 14--17; Section 6 on printed p. 17 and the remark on p. 14 (PDF pp. 5 and 2 of the TU/e portal PDF), read on the page images. The edition read is identified in the source digest.

Read depth. Claims checked: the two passages were read clause by clause on the page images. A conjecture has no proof to check.

The normalization defect

As worded, the first two expressions are missing a factor of rr: the average rr-span is r/nr/n, so Λr\Lambda_r and λr\lambda_r are compared with rr rather than with 11. The community database marks the site's statement as needing this correction ("ambiguous statement"; a missing factor of rr), and Korsky's 2026 preprint restates the conjecture as Aˉr−r→∞\bar A_r-r\to\infty, r−A‾r→∞r-\underline A_r\to\infty, r(μr−1)→∞r(\mu_r-1)\to\infty, a corrected paraphrase rather than the note's wording.

Dependencies

None.

Bears on

  • Problem 1221: this passage is the problem. The site's wording inherits the normalization slip; the problem page shows the mean-normalized form as its corrected Statement and records the 2026 preprint that claims all three parts of it.