%I #4 Jan 11 2013 10:43:15
%S 17,1033,66077,4413085,299240982,20386200143,1390606420092,
%T 94886635979289,6474877285339469,441834716000600936,
%U 30149910032297404248,2057359679730562832221,140388996646009895985892
%N Number of nX4 arrays of occupancy after each element stays put or moves to some horizontal, diagonal or antidiagonal neighbor, with no occupancy greater than 2
%C Column 4 of A221345
%H R. H. Hardin, <a href="/A221343/b221343.txt">Table of n, a(n) for n = 1..16</a>
%e Some solutions for n=3
%e ..2..1..0..2....2..0..0..1....2..2..0..2....1..2..0..0....1..2..0..1
%e ..0..2..2..1....2..0..1..2....1..0..2..0....0..1..2..0....1..1..1..0
%e ..1..0..0..1....0..2..0..2....0..1..2..0....2..1..2..1....0..2..2..1
%K nonn
%O 1,1
%A _R. H. Hardin_ Jan 11 2013