PROVED (LEAN), in the site's label. Martin's Theorem 2 (Acta Arith. 95 (2000), no. 3, 231--260; refereed) gives, for every positive rational $r$ and all $t\ge t_0(r)$, $M_t(r)=t/(1-e^{-r})+O_r(t\log\log3t/\log3t)$, best possible; at $r=1$ this is $f(k)=\frac{e}{e-1}k+O(k\log\log k/\log k)$, so the answer is yes; the standing in the frontmatter derives from the accepted claim page Martin 1998. The Lean suffix of the site's label refers to a public Lean proof of the statement in Boris Alexeev's repository, recorded under Formalization and the Lean label below; the corpus has not built it, and no local kernel credit is claimed.