login
Number of nX4 arrays of occupancy after each element moves to some horizontal or vertical neighbor, without move-in move-out left turns
1

%I #4 Jan 21 2013 18:12:15

%S 4,139,5741,229150,9062913,357398390,14082457465,554737340774,

%T 21850499916432,860643590653662,33898578158279334,1335175267629518426,

%U 52588965509249101477,2071337262002534945067,81584368108175368557177

%N Number of nX4 arrays of occupancy after each element moves to some horizontal or vertical neighbor, without move-in move-out left turns

%C Column 4 of A221676

%H R. H. Hardin, <a href="/A221675/b221675.txt">Table of n, a(n) for n = 1..27</a>

%e Some solutions for n=3

%e ..1..0..1..1....1..2..3..1....1..1..1..1....0..1..3..1....2..1..0..1

%e ..2..1..0..2....1..0..0..0....0..1..2..1....1..0..1..0....2..1..1..2

%e ..0..1..1..2....1..0..1..2....0..1..2..1....2..1..1..1....1..1..0..0

%K nonn

%O 1,1

%A _R. H. Hardin_ Jan 21 2013