 Its name comes from the De Bruijn sequence, which can be considered a special case where "n" is 1 (one dimension).One of the main open questions regarding De Bruijn tori is whether a De Bruijn torus for a particular alphabet size can be constructed for a given "m" and "n".It is known that these always exist when "n" = 1, since then we simply get the De Bruijn sequences, which always exist.