
OFFSET

1,1


COMMENTS

Here the semigroup is under boolean matrix multiplication (not the same as GF(2) matrix multiplication). It is known that a(4) >= 24846, generated by the three matrices [[0,0,0,1],[1,0,0,0],[0,1,0,0],[0,0,1,0]] and [[0,0,0,1],[0,0,1,0],[0,1,0,0],[1,0,0,1]] and [[0,0,0,0],[0,0,0,1],[0,0,1,0],[0,1,0,0]].


LINKS



EXAMPLE

For n = 1 the maximum size is 2, generated by the three matrices [0] and [1] and [1].
For n = 2 the maximum size is 16, generated by the three matrices [[0,1],[1,1]] and [[0,1],[1,0]] and [[0,0],[0,1]].
For n = 3 the maximum size is 440, generated by the three matrices [[0,0,1],[1,0,0],[0,1,0]] and [[0,0,1],[0,1,0],[1,0,1]] and [[0,0,0],[0,0,1],[0,1,0]].


CROSSREFS



KEYWORD

nonn,hard,more,bref


AUTHOR



STATUS

approved

