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A233240 Number of 2 X n 0..5 arrays with no element x(i,j) adjacent to value 5-x(i,j) horizontally, diagonally or antidiagonally, top left element zero, and 1 appearing before 2 3 and 4, and 2 appearing before 3 in row major order.

%I A233240 #8 Oct 10 2018 15:20:22
%S A233240 3,19,271,4504,79201,1419889,25622596,463384804,8386411051,
%T A233240 151815188839,2748457460746,49759306786354,900872721644401,
%U A233240 16309994546050789,295287194569964896,5346081195735699904,96789118201657881751
%N A233240 Number of 2 X n 0..5 arrays with no element x(i,j) adjacent to value 5-x(i,j) horizontally, diagonally or antidiagonally, top left element zero, and 1 appearing before 2 3 and 4, and 2 appearing before 3 in row major order.
%H A233240 R. H. Hardin, <a href="/A233240/b233240.txt">Table of n, a(n) for n = 1..210</a>
%F A233240 Empirical: a(n) = 23*a(n-1) - 81*a(n-2) - 143*a(n-3) + 82*a(n-4) + 120*a(n-5) for n>6.
%F A233240 Empirical g.f.: x*(3 - 50*x + 77*x^2 + 239*x^3 + 31*x^4 - 75*x^5) / ((1 - x)*(1 + x)*(1 - 6*x)*(1 - 17*x - 20*x^2)). - _Colin Barker_, Oct 10 2018
%e A233240 Some solutions for n=5:
%e A233240 ..0..1..2..0..4....0..1..2..1..0....0..0..1..2..5....0..1..1..2..2
%e A233240 ..0..1..2..4..2....1..0..3..0..0....1..3..1..2..5....5..3..1..5..2
%Y A233240 Row 2 of A233239.
%K A233240 nonn
%O A233240 1,1
%A A233240 _R. H. Hardin_, Dec 06 2013