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%I
%S 1,1,77,5385,545426,79230924,15755497776,4122239926855
%N Number of nX3 arrays containing 3 indistinguishable copies of 1..n with rows and columns in lexicographically strictly increasing order
%C Column 3 of A180839
%e Some solutions for 3X3
%e ..1..1..2....1..1..2....1..1..2....1..1..2....1..1..2....1..1..2....1..1..2
%e ..1..2..3....1..2..2....1..2..3....1..2..3....1..3..2....1..3..3....1..3..3
%e ..2..3..3....3..3..3....3..3..2....3..2..3....2..3..3....2..3..2....2..2..3
%e ...
%e ..1..1..2....1..1..2....1..1..2....1..1..3....1..1..3....1..1..3....1..1..3
%e ..1..3..2....1..3..2....1..3..3....1..2..2....1..2..3....1..2..3....1..2..2
%e ..3..3..2....3..2..3....3..2..2....2..3..3....2..3..2....2..2..3....3..3..2
%e ...
%e ..1..1..3....1..1..3....1..1..3....1..1..3....1..1..3....1..1..3....1..1..1
%e ..1..2..2....1..2..3....1..3..2....1..3..2....1..3..3....1..3..2....2..2..3
%e ..3..2..3....3..2..2....2..3..2....2..2..3....2..2..2....3..2..2....2..3..3
%e ...
%e ..1..1..2....1..1..2....1..1..2....1..1..2....1..1..2....1..1..2....1..1..2
%e ..2..3..1....2..3..1....2..3..1....2..3..2....2..3..2....2..3..3....2..3..3
%e ..2..3..3....3..3..2....3..2..3....3..3..1....3..1..3....3..1..2....3..2..1
%K nonn
%O 1,3
%A _R. H. Hardin_ Sep 20 2010
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