User blog comment:Jiawhien/brace1/@comment-25418284-20130608011343

I believe the formal definition of the single-argument function is

\[\text{Brace}(n) = \left\lfloor\frac{n10^{dn}}{10^d - 1}\right\rfloor\]

where \(d = \lfloor\log_10 n\rfloor + 1\).