%I #4 Jan 02 2013 19:44:49
%S 2,49,656,12544,200072,3485689,58132316,990486784,16699002692,
%T 282999528529,4783766470826,80965479678724,1369496232351362,
%U 23171487659654569,391996208325992186,6631958618350959364
%N Number of nX3 arrays of occupancy after each element moves to some horizontal or vertical neighbor, with no occupancy greater than 2
%C Column 3 of A221139
%H R. H. Hardin, <a href="/A221134/b221134.txt">Table of n, a(n) for n = 1..29</a>
%F Empirical: a(n) = 21*a(n1) 1450*a(n3) +4782*a(n4) 372*a(n5) +1450*a(n6) +69*a(n8) +a(n9)
%e Some solutions for n=3
%e ..2..1..1....1..2..0....0..2..2....2..1..0....0..2..2....0..1..2....0..2..2
%e ..1..0..1....1..2..0....1..1..1....2..1..2....0..2..1....2..0..1....1..0..1
%e ..0..2..1....1..2..0....0..1..1....0..0..1....0..2..0....2..1..0....2..1..0
%K nonn
%O 1,1
%A _R. H. Hardin_ Jan 02 2013
