Problem 11286. - Marc LeBrun; David L. Applegate; Neil J. A. Sloane (Am. Math. Mon., 2007)

Descending Dungeons and Iterated Base-Changing. - David L. Applegate; Marc LeBrun; Neil J. A. Sloane (The Mathematics of Preference, Choice and Order, 2009)

Descending Dungeons: 11286 [2007, 358]. - Marc LeBrun (Am. Math. Mon., 2009)