PGAGetIntegerFromGrayCode(3) on Linux
The text 18a9d989a957, as Debian 3.1 (Sarge), Debian 3.0 (Woody), Debian 2.2 (Potato), Debian 2.1 (Slink), Debian 2.0 (Hamm), Debian 1.3 (Bo), Debian 1.2 (Rex) shipped it. The page shows this text now.
interpets a binary reflected Gray code sequence as encoding an integer value and returns the integer value it represents.