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%I #5 Dec 18 2015 18:18:37
%S 1,3,36,813,44379,6022992,2110707595,1972236759492
%N Number of n X n binary arrays indicating whether each 2X2 subblock of a larger binary array has lexicographically nondecreasing rows and columns, for some larger (n+1)X(n+1) binary array with rows and columns of the latter in lexicographically nondecreasing order
%C Diagonal of A227256
%e Some solutions for n=4
%e ..1..0..1..1....1..1..0..0....1..1..1..1....1..1..1..0....1..1..1..1
%e ..0..1..1..1....1..0..1..1....1..1..0..0....1..1..0..0....1..1..0..1
%e ..0..1..1..1....1..0..1..1....1..0..0..1....1..0..1..1....1..0..1..0
%e ..1..1..1..1....1..1..1..0....0..0..1..0....0..1..1..1....1..1..0..1
%K nonn
%O 1,2
%A _R. H. Hardin_ Jul 04 2013