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%I #17 Sep 03 2017 21:28:42
%S 1,2,72,4140,4111116,48183195384
%N Number of 2n X 2n Takuzu grids.
%C A Takuzu grid is a 2n X 2n zero-one matrix with the following properties:
%C 1. Every row and every column has n zeros and n ones.
%C 2. No row or column has three consecutive zeros or three consecutive ones.
%C 3. All rows are distinct, and all columns are distinct (but a row may be the same as a column).
%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Takuzu">Takuzu</a>
%e The following is a 4 X 4 Takuzu grid:
%e [ 0 1 1 0 ]
%e [ 1 0 0 1 ]
%e [ 0 0 1 1 ]
%e [ 1 1 0 0 ]
%Y Cf. A058527.
%Y Number of possible rows equals A003440.
%K nonn,more
%O 0,2
%A _Brian Kell_, Dec 30 2014
%E a(5) from _Frans J. Faase_, Dec 14 2015
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