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%I #2 Mar 31 2012 12:35:48
%S 1,1,9,72,678,7719,102963,1573764,27143466,521698683,11059018599,
%T 256349691978,6451098232944
%N Number of nX2 arrays containing 2 indistinguishable copies of 1..n with rows and columns in lexicographically strictly increasing order
%C Column 2 of A180839
%e Some solutions for 4X2
%e ..1..1....1..1....1..1....1..1....1..1....1..1....1..1....1..1....1..1....1..3
%e ..2..3....2..3....2..3....2..3....2..3....2..2....2..4....2..4....2..4....1..4
%e ..3..2....3..4....2..4....2..4....4..2....3..4....3..3....3..2....3..2....3..2
%e ..4..4....4..2....4..3....3..4....4..3....4..3....4..2....4..3....3..4....4..2
%e ...
%e ..1..3....1..3....1..3....1..3....1..3....1..3....1..3....1..3....1..3....1..3
%e ..1..4....1..4....1..4....1..4....1..4....3..2....2..1....2..1....2..1....2..1
%e ..2..3....2..3....2..2....2..2....2..4....4..1....3..2....3..4....2..3....2..4
%e ..4..2....2..4....4..3....3..4....3..2....4..2....4..4....4..2....4..4....4..3
%e ...
%e ..1..3....1..3....1..3....1..3....1..3....1..3....1..3....1..3....1..3....1..2
%e ..2..1....2..1....2..3....2..3....2..2....2..2....2..2....2..4....2..4....1..3
%e ..2..4....4..2....2..4....4..1....3..1....3..4....4..1....3..1....3..2....3..2
%e ..3..4....4..3....4..1....4..2....4..4....4..1....4..3....4..2....4..1....4..4
%K nonn
%O 1,3
%A _R. H. Hardin_ Sep 20 2010