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%I #4 Mar 31 2012 12:36:08
%S 16,580,59008,18555136,19210448896,68711440384000,884085911344119808,
%T 42474221110291056295936
%N Number of (n+1)X(n+1) 0..3 arrays with diagonal zero and the i,j-th 2X2 subblock sum equal to the j,i-th 2X2 subblock sum
%C Column 3 of A187408
%e Some solutions for 5X5
%e ..0..2..0..0..0....0..2..0..2..2....0..2..0..2..2....0..0..0..2..2
%e ..0..0..0..2..3....2..0..3..0..0....2..0..2..1..1....0..0..2..1..2
%e ..2..0..0..0..3....0..3..0..2..1....2..0..0..0..3....2..0..0..0..1
%e ..0..0..2..0..3....2..0..2..0..1....0..3..0..0..1....2..1..2..0..2
%e ..2..3..3..1..0....1..1..0..2..0....2..1..1..3..0....3..1..0..1..0
%K nonn
%O 1,1
%A _R. H. Hardin_ Mar 09 2011
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