%I #4 Dec 18 2015 18:18:08
%S 0,0,2,0,2,8,0,0,19,26,0,0,22,236,66,0,0,22,957,1726,141,0,0,22,1942,
%T 23267,8471,267,0,0,0,2382,176941,285622,31732,463,0,0,0,2418,787584,
%U 5996922,2223733
%N T(n,k)=Number of lower triangular n X n arrays of integers 0 upwards introduced in row major order, with each element unique in its row and column, and containing the value n(n+1)/2-k-1
%C Table starts
%C ...0.....0.......0.......0......0....0.0.0.0
%C ...2.....2.......0.......0......0....0.0.0
%C ...8....19......22......22.....22....0.0
%C ..26...236.....957....1942...2382.2418
%C ..66..1726...23267..176941.787584
%C .141..8471..285622.5996922
%C .267.31732.2223733
%C .463
%e Some solutions for n=4 k=4
%e ..0........0........0........0........0........0........0........0
%e ..1.0......1.0......1.2......1.2......1.2......1.2......1.2......1.2
%e ..2.3.1....2.3.4....3.0.1....3.1.4....3.4.1....3.4.2....3.4.5....3.0.4
%e ..4.1.0.5..3.5.2.0..2.3.4.5..4.0.1.5..4.1.5.0..4.0.5.2..2.0.4.3..5.6.7.2
%K nonn,tabl
%O 1,3
%A _R. H. Hardin_ Apr 24 2012