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Claim. The number of maximal sum-free subsets of $\{1,\ldots,n\}$ satisfies

$$f_m(n)\le2^{3n/8+o(n)},$$

where $f_m(n)$ is the count of Problem 877. Since $3/8<1/2$, this gives $f_m(n)=o(2^{n/2})$ and answers the displayed question yes, improving the exponent $1/2-2^{-28}$ of Łuczak and Schoen; the exact exponent $1/4$ is the later claim of Balogh, Liu, Sharifzadeh and Treglown on its own page. The source is G. Wolfovitz, Bounds on the number of maximal sum-free sets, European J. Combin. 30 (2009), no. 7, 1718--1723, cited as [Wo09] on the problem page. The paper is not held: the bound is quoted from the introductions of the two papers of Balogh, Liu, Sharifzadeh and Treglown (2015 and 2018, p. 2 of each preprint), which state it in this form after Łuczak and Schoen's bound and before their own. An extended abstract with the same title appeared in Electron. Notes Discrete Math. 29 (2007), 321--325 (DOI 10.1016/j.endm.2007.07.055); whether it states this bound is not recorded, so it is not listed as a posting and the page is named by the journal paper's date.

Depends on. No wiki page; the claim rests on the cited paper.

Acceptance. Refereed: the paper is a research article in the European Journal of Combinatorics (Crossref record read: volume 30, issue 7, print issue October 2009; the record was created 9 April 2009, the date that names this page). The site's curator does not mention Wolfovitz in the problem's commentary, so no reviewed evidence is listed; the two refereed papers of 2015 and 2018 cite the bound as an intermediate step between Łuczak and Schoen's answer and their own. The paper's read status is unread, so no further evidence is listed.