Research notes on every problem, and a library of the papers behind them. Built from the open erdos repository.
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Claim. K. Benli, C. Dartyge, C. Dombrowsky, P. Pollack and L. Thompson, On the digits of the sum of proper divisors, arXiv:2607.18981 (v1, 21 July 2026), Theorem 1.4: "Fix , , and a nonempty set . For all sufficiently large , the number of for which has all of its digits in base restricted to digits in is " (result page). The paper cites the earlier Theorem 1.8 of Benli, Cesana, Dartyge, Dombrowsky and Thompson for and proves the case , omitted there, by a separate elementary argument in its Appendix A. It keeps the general assertion as its Conjecture 1.3 and says that it remains open.
Covers. The base- missing-digit targets, which the earlier theorem omits; with it, the missing-digit targets in every base . The general assertion stays open.
Depends on. The 2023 missing-digit theorem for .
Acceptance. Claimed: an arXiv preprint, with no refereed publication or curator credit on record.