%I #4 Jan 25 2013 09:32:58
%S 21,2631,311500,36959565,4383899151,519828193272,61646570104772,
%T 7310747898489930,866987511530643810,102816641533831938240,
%U 12193094561710087236373,1445987266172531006933514
%N Number of nX4 arrays of occupancy after each element stays put or moves to some horizontal, diagonal or antidiagonal neighbor, without move-in move-out left turns
%C Column 4 of A221780
%H R. H. Hardin, <a href="/A221779/b221779.txt">Table of n, a(n) for n = 1..54</a>
%e Some solutions for n=3
%e ..0..2..1..0....0..2..1..2....0..1..3..2....0..1..0..2....0..3..0..1
%e ..1..2..0..0....0..1..0..2....1..0..0..1....0..1..2..0....1..0..0..3
%e ..0..2..3..1....3..0..0..1....1..0..3..0....2..2..0..2....0..1..2..1
%K nonn
%O 1,1
%A _R. H. Hardin_ Jan 25 2013
|