|
%I #5 Mar 31 2012 12:35:52
%S 12,81,776,6561,59292,531441,4786704,43046721,387440172,3486784401,
%T 31381355016,282429536481,2541867422652,22876792454961,
%U 205891156016784,1853020188851841,16677181828806732,150094635296999121
%N Number of nX2 0..3 arrays with no element equal to the sum mod 4 of its horizontal and vertical neighbors
%C Column 2 of A183508
%H R. H. Hardin, <a href="/A183504/b183504.txt">Table of n, a(n) for n = 1..200</a>
%F Empirical: a(n)=9*a(n-1)+81*a(n-4)-729*a(n-5)+81*a(n-8)-729*a(n-9)-6561*a(n-12)+59049*a(n-13)
%e Some solutions for 3X2
%e ..3..2....1..0....2..3....1..1....2..3....1..0....0..3....2..2....1..2....2..0
%e ..2..1....3..0....2..2....3..3....1..2....2..0....3..1....1..3....2..3....0..0
%e ..3..2....1..0....3..0....2..0....3..0....2..1....1..1....1..3....3..0....0..3
%K nonn
%O 1,1
%A _R. H. Hardin_ Jan 05 2011
| 