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%I
%S 90,1456,16262,144248,1097986,7500960,47315662,280898512,1590567658,
%T 8673625464,45876777622,236629296200,1195160833298,5930230507888,
%U 28981276937886,139784115993376,666528024959098,3146266602049672
%N Number of (n+1)X(n+1) 0..3 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing x(i,j)+x(i-1,j) in the j direction
%C Diagonal of A250877
%H R. H. Hardin, <a href="/A250869/b250869.txt">Table of n, a(n) for n = 1..35</a>
%e Some solutions for n=4
%e ..2..2..2..2..2....2..2..2..2..2....0..0..0..0..0....2..2..2..2..2
%e ..2..2..2..2..2....1..1..1..1..1....0..0..0..0..0....0..0..0..0..0
%e ..1..2..2..2..2....0..0..0..1..1....0..0..1..1..1....3..3..3..3..3
%e ..0..1..1..1..1....2..2..2..3..3....2..2..3..3..3....0..0..0..1..1
%e ..1..3..3..3..3....2..2..2..3..3....0..0..1..3..3....1..1..1..2..3
%K nonn
%O 1,1
%A _R. H. Hardin_, Nov 28 2014
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