Editing Torus (section)

== de Bruijn torus ==
{{main|de Bruijn torus}}
[[File:de_bruijn_torus_3x3.stl|thumb|250px|link=http://viewstl.com/classic/?embedded&url=http://upload.wikimedia.org/wikipedia/commons/1/1e/De_bruijn_torus_3x3.stl&bgcolor=black|[[STL (file format)|STL]] model of de Bruijn torus {{nowrap|(16,32;3,3)<sub>2</sub>}} with 1s as panels and 0s as holes in the mesh &ndash; with consistent orientation, every 3×3 matrix appears exactly once]]
In [[combinatorics|combinatorial]] mathematics, a ''de Bruijn torus'' is an [[matrix (mathematics)|array]] of symbols from an alphabet (often just 0 and 1) that contains every {{math|''m''}}-by-{{math|''n''}} [[matrix (mathematics)|matrix]] exactly once.  It is a torus because the edges are considered wraparound for the purpose of finding matrices. Its name comes from the [[De Bruijn sequence]], which can be considered a special case where {{math|''n''}} is&nbsp;1 (one dimension).