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A (0,1)-matrix in the first quadrant read by downward antidiagonals: an example of a uniformly recurrent 2-D word in which row 0 is non-recurrent.
0

%I #21 Nov 03 2020 05:37:27

%S 1,1,0,1,1,0,1,0,1,0,1,1,1,1,0,1,0,1,0,1,0,1,1,0,1,1,1,0,1,0,1,0,1,0,

%T 1,0,1,1,1,1,1,1,1,1,0,1,0,1,0,1,0,1,0,1,0

%N A (0,1)-matrix in the first quadrant read by downward antidiagonals: an example of a uniformly recurrent 2-D word in which row 0 is non-recurrent.

%C Proposition 5 of Charlier et al. (2020) gives the formal definition of the matrix.

%D Charlier, Émilie, Svetlana Puzynina, and Élise Vandomme. "Recurrence along directions in multidimensional words." Discrete Mathematics 343.10 (2020): 112006.

%H Émilie Charlier, Svetlana Puzynina, and Élise Vandomme, <a href="https://arxiv.org/abs/1907.00192">Recurrence along directions in multidimensional words</a>, arXiv:1907.00192 [math.CO], 2019-2020.

%e The array begins:

%e ...........

%e 1 1 1 1 1 1 1 1 1 1 1 1 ...

%e 1 0 0 0 1 0 0 0 1 0 0 0 ...

%e 1 1 1 1 1 1 1 1 1 1 1 1 ...

%e 1 0 1 0 1 0 1 0 1 0 1 0 ...

%e 1 1 1 1 1 1 1 1 1 1 1 1 ...

%e 1 0 0 0 0 0 0 0 1 0 0 0 ...

%e 1 1 1 1 1 1 1 1 1 1 1 1 ...

%e 1 0 1 0 1 0 1 0 1 0 1 0 ...

%e 1 1 1 1 1 1 1 1 1 1 1 1 ...

%e 1 0 0 0 1 0 0 0 1 0 0 0 ...

%e 1 1 1 1 1 1 1 1 1 1 1 1 ...

%e 1 0 1 0 1 0 1 0 1 0 1 0 ...

%e 1 1 1 1 1 1 1 1 1 1 1 1 ...

%e 1 0 0 0 0 0 0 0 0 0 0 0 ...

%e This is to be read from bottom to top and left to right.

%e The initial antidiagonals (starting in bottom left corner) are:

%e 1,

%e 1,0,

%e 1,1,0,

%e 1,0,1,0,

%e 1,1,1,1,0,

%e 1,0,1,0,1,0,

%e 1,1,0,1,1,1,0,

%e 1,0,1,0,1,0,1,0,

%e 1,1,1,1,1,1,1,1,0,

%e 1,0,1,0,1,0,1,0,1,0,

%e ...

%Y Cf. A338353.

%K nonn,tabl,more

%O 0

%A _N. J. A. Sloane_, Nov 02 2020