%I #4 Jan 13 2013 20:27:58
%S 17,1035,68006,4616125,318041768,22033399959,1529080824804,
%T 106164820551146,7371759230687250,511872801045551424,
%U 35542384488014253577,2467887742431130823456,171356388233296069988322
%N Number of nX4 arrays of occupancy after each element stays put or moves to some horizontal, vertical or antidiagonal neighbor, with no occupancy greater than 2
%C Column 4 of A221378
%H R. H. Hardin, <a href="/A221376/b221376.txt">Table of n, a(n) for n = 1..45</a>
%e Some solutions for n=3
%e ..1..1..0..1....0..1..1..0....0..2..2..0....1..0..1..0....2..0..1..0
%e ..2..0..1..2....0..1..2..2....2..1..2..1....0..2..2..0....0..0..2..2
%e ..2..1..1..0....1..2..1..1....0..0..0..2....2..2..1..1....1..1..1..2
%K nonn
%O 1,1
%A _R. H. Hardin_ Jan 13 2013
|