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Claim. M.-M. Ma and Y.-G. Chen, On $d$-complete sequences of integers, J. Number Theory 164 (2016), 1--12 (online 3 February 2016). The paper's abstract states the theorem: for every integer $p>6$ with $(p,10)=1$, if there is a number $c=c(p)$ such that every integer $n$ with $c<n<25pc$ is a sum of distinct terms of $\{2^\alpha5^\beta p^\gamma\}$ no one of which divides another, then that sequence is $d$-complete; and the sequence is $d$-complete for $p\in\{9,21,23,27,29,31\}$. The abstract places the work after Erdős and Lewin's remark that they could not prove the case $p=23$. For Problem 123 this settles the triples $(2,5,c)$ for those six $c$, and reduces each other $c>6$ coprime to $10$ to a finite check over one interval.

Covers. The triples $(2,5,c)$ for $c\in\{9,21,23,27,29,31\}$. The criterion for other $c>6$ coprime to $10$ is a reduction to a finite check, not a settled case. Not covered: every other triple. Chen and Yu's later theorem (its claim page) contains these six triples.

Depends on. Nothing in this wiki; the result rests on the cited paper.

Read depth. The statement is taken from the paper's abstract; the body of the paper, which the library does not hold, was not read.

Acceptance. Refereed: Journal of Number Theory 164 (July 2016). The site's commentary lists the result, but the site credits the settlement of the problem to Snyder's proof, so the commentary is not reviewed evidence for this paper.