A221810 - OEIS

%I #4 Jan 26 2013 06:58:32

%S 1,10,34,214,1016,5429,27535,142858,733811,3785852,19494390,100466360,

%T 517573094,2666814576,13739888978,70792474153,364741397621,

%U 1879254550345,9682444806825,49886719497414,257030490240855,1324294082316952

%N Number of 2Xn arrays of occupancy after each element moves to some horizontal, vertical or antidiagonal neighbor, without move-in move-out straight through or left turns

%C Row 2 of A221809

%H R. H. Hardin, <a href="/A221810/b221810.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = a(n-1) +18*a(n-2) +22*a(n-3) -14*a(n-4) -39*a(n-5) -44*a(n-6) -6*a(n-7) +7*a(n-8) +3*a(n-9) +4*a(n-10) +a(n-11)

%e Some solutions for n=3

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

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

%K nonn

%O 1,2

%A _R. H. Hardin_ Jan 26 2013