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%I #7 Oct 05 2018 12:00:25
%S 3,51,381,3015,24651,198945,1607067,12991131,104990445,848511855,
%T 6857610579,55422433089,447917887827,3620023336611,29256629564061,
%U 236448855048951,1910953595190267,15444116384727393,124817646797556651
%N Number of n X 2 0..2 arrays with every 0 next to a 1 and every 1 next to a 2 horizontally, vertically, diagonally or antidiagonally.
%H R. H. Hardin, <a href="/A232453/b232453.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 6*a(n-1) + 12*a(n-2) + 39*a(n-3).
%F Empirical g.f.: 3*x*(1 + 11*x + 13*x^2) / (1 - 6*x - 12*x^2 - 39*x^3). - _Colin Barker_, Oct 05 2018
%e Some solutions for n=6:
%e ..1..0....1..1....0..2....0..2....1..1....0..1....1..0....0..1....0..2....1..1
%e ..2..1....2..2....1..2....2..1....2..0....1..2....2..1....2..2....1..0....0..2
%e ..1..0....1..2....1..2....1..0....2..2....1..0....2..2....2..2....0..0....0..2
%e ..0..0....1..2....0..1....1..1....2..2....2..2....2..2....1..0....0..1....1..1
%e ..0..1....2..1....1..2....2..0....1..2....0..2....1..2....0..2....1..2....2..1
%e ..2..2....0..1....0..0....1..0....0..1....2..1....1..1....0..1....2..1....1..2
%Y Column 2 of A232459.
%K nonn
%O 1,1
%A _R. H. Hardin_, Nov 24 2013