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%I #4 Jan 21 2013 07:27:50
%S 1,3,27,410,10055,353654,17052210,1075295220,86037489675,
%T 8510611773950,1020010974544958,145633667181394028,
%U 24424236713657975558,4754016566455947216412,1062903928921857001102308
%N Number of 2Xn arrays with each row a permutation of 1..n having at least as many downsteps as the preceding row
%C Row 2 of A221623
%H R. H. Hardin, <a href="/A221624/b221624.txt">Table of n, a(n) for n = 1..16</a>
%e Some solutions for n=3
%e ..2..3..1....2..3..1....2..1..3....3..1..2....2..1..3....1..3..2....1..2..3
%e ..3..2..1....1..3..2....2..3..1....2..1..3....2..1..3....2..3..1....1..2..3
%K nonn
%O 1,2
%A _R. H. Hardin_ Jan 21 2013
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