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%I #9 Sep 22 2018 11:51:48
%S 0,6,86,820,8154,82576,833986,8417644,84971714,857764344,8658840234,
%T 87407976260,882353220314,8907050256960,89913587800402,
%U 907646529844380,9162377384021426,92491026597941000,933664882212237754
%N Number of n X 2 0..3 arrays x(i,j) with each element horizontally, vertically, diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 4, and upper left element zero.
%H R. H. Hardin, <a href="/A230782/b230782.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 10*a(n-1) - 3*a(n-2) + 44*a(n-3) - 40*a(n-4) + 8*a(n-5) - 192*a(n-6).
%F Empirical g.f.: 2*x^2*(3 + 13*x - 11*x^2 - 26*x^3 - 24*x^4) / (1 - 10*x + 3*x^2 - 44*x^3 + 40*x^4 - 8*x^5 + 192*x^6). - _Colin Barker_, Sep 22 2018
%e Some solutions for n=3:
%e ..0..3....0..1....0..3....0..2....0..3....0..1....0..2....0..0....0..2....0..3
%e ..0..1....2..1....2..1....1..3....3..1....1..2....3..1....3..1....3..1....3..1
%e ..3..2....0..3....0..3....1..2....2..0....3..0....2..0....0..2....0..3....2..1
%Y Column 2 of A230787.
%K nonn
%O 1,2
%A _R. H. Hardin_, Oct 30 2013
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