%I #4 Jan 03 2013 09:39:53
%S 8,352,14704,609961,25266305,1046229704,43318295565,1793512771275,
%T 74256503785519,3074423327838949,127289505511741394,
%U 5270131676800319948,218197773791764622997,9033980715508142596386,374031347287341441297064
%N Number of nX3 arrays of occupancy after each element stays put or moves to some horizontal, vertical or antidiagonal neighbor
%C Column 3 of A221165
%H R. H. Hardin, <a href="/A221163/b221163.txt">Table of n, a(n) for n = 1..16</a>
%e Some solutions for n=3
%e ..3..0..0....1..0..3....1..2..0....1..2..0....1..3..0....2..1..0....1..0..1
%e ..0..1..2....1..0..0....1..0..2....0..1..2....0..0..0....1..2..2....1..0..2
%e ..3..0..0....3..0..1....0..2..1....3..0..0....2..0..3....0..1..0....4..0..0
%K nonn
%O 1,1
%A _R. H. Hardin_ Jan 03 2013