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%I #11 Jul 21 2018 15:52:19
%S 10,568,18226,518320,14230810,386357608,10450787266,282343443040,
%T 7624822644010,205884158525848,5558997804436306,150094070437926160,
%U 4052550069287319610,109418943377927449288,2954312294768569509346
%N Number of n X 3 0..2 arrays with no column j greater than column j-1 in all rows.
%C Column 3 of A212930.
%H R. H. Hardin, <a href="/A212925/b212925.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 37*a(n-1) -279*a(n-2) +243*a(n-3).
%F Explicit formula: a(n) = 27^n - 2*9^n + 1. - _Vaclav Kotesovec_, May 31 2012
%F Empirical g.f.: 2*x*(5 + 99*x) / ((1 - x)*(1 - 9*x)*(1 - 27*x)). - _Colin Barker_, Jul 21 2018
%e Some solutions for n=3:
%e ..2..2..2....0..1..1....1..2..1....1..0..1....0..0..0....2..1..2....2..1..0
%e ..0..0..2....0..0..2....2..1..2....1..2..2....1..2..0....1..2..2....2..1..2
%e ..1..2..0....0..0..2....1..0..2....2..1..2....1..2..2....1..2..0....2..1..1
%Y Cf. A212930.
%K nonn
%O 1,1
%A _R. H. Hardin_, May 31 2012