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%I #3 Mar 31 2012 12:35:49
%S 140,49772,33235358,27896484332,26012734507190,25785064658274014,
%T 26631749414632177802,28342597507242978860012,
%U 30862541359435652055581702,34221243248277031078812700022,38507504930060734566868274154362
%N Number of (4*n)X4 binary matrices with all row sums equal and all column sums equal
%C Row 4 of A181236
%H R. H. Hardin, <a href="/A181238/b181238.txt">Table of n, a(n) for n=1..22</a>
%e Some solutions for 4X4
%e ..1..1..0..1....1..1..0..0....0..1..0..1....0..1..0..0....1..0..0..1
%e ..1..0..1..1....0..0..1..1....1..0..0..1....0..0..0..1....1..1..0..0
%e ..0..1..1..1....1..0..0..1....0..1..1..0....0..0..1..0....0..0..1..1
%e ..1..1..1..0....0..1..1..0....1..0..1..0....1..0..0..0....0..1..1..0
%K nonn
%O 1,1
%A _R. H. Hardin_ Oct 10 2010
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