Name of binary encoding scheme for integer numbers I once found on Wikipedia a nice technique for encoding $k \in (2^{n-1}, 2^n)$ uniformly distributed integer numbers with less then $\log_2n$ average bits/symbol, thanks to a simple to compute variable length code. Basically it used $\log_2n$ for some symbols and $\log_2n - 1$ for some others. 

Unfortunately all my Googling has failed me. I recall something similar to "variable length binary", but I keep ending on VLQ which are a different beast. Since I know your memory better than mine, can you help me?
The technique idea is perfectly described in Yuval Filmus answer. Even if slightly different, it is called Truncated binary encoding in Wikipedia. I couldn't find an original source for that, apart from a mention in a patent, in this book, or in this Google API
Another mention can be found in the ACM ICPC 2011–2012, Northeastern European Regional Contest, November 27, 2011.