The de Bruijn Torus

​
ternary2×2
5
quaternary2×2
20
binary3×2
6
​
binary3×3
7
In the de Bruijn sequence
0010203112132233
, all items of order two from the alphabet
{0,1,2,3}
of size four are cyclically represented. Those items are
00
,
01
,
10
,
02
and so on.
In the de Bruijn sequence
0000100110101111
, all order-four items from the size-two alphabet
{0,1}
are cyclically represented. In this case, the items are
0000
,
0001
,
0010
and so on.
In general, the order-
n
de Bruijn sequence for a size-
k
alphabet
B(k,n)
has length
n
k
. There are
n-1
k
(k!)
n
k
different
B(k,n)
sequences.
For a de Bruijn torus, all
(m,n)
-matrices from a size-
k
alphabet have toroidal representation in an array.
In this Demonstration, de Bruijn tori for ternary
2×2
, quaternary
2×2
, binary
3×2
and binary
3×3
are shown. Choose an index number with a slider; the de Bruijn torus is rotated to place the corresponding matrix in the upper-left corner of the array.

External Links

de Bruijn Sequence (Wolfram MathWorld)
De Bruijn Sequences
De Bruijn Graph Arcs
Patterns from de Bruijn Sequences

Permanent Citation

Ed Pegg Jr
​
​"The de Bruijn Torus"​
​http://demonstrations.wolfram.com/TheDeBruijnTorus/​
​Wolfram Demonstrations Project​
​Published: January 1, 1999