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A232371 Number of nX3 0..3 arrays with every 0 next to a 1, every 1 next to a 2 and every 2 next to a 3 horizontally, diagonally or antidiagonally, and no adjacent values equal.

%I A232371 #6 Jul 23 2025 07:21:54
%S A232371 4,74,586,4550,36574,292122,2324142,18574882,148225606,1182879814,
%T A232371 9441116934,75346596778,601334070966,4799220047514,38302112010658,
%U A232371 305686073938078,2439655331781498,19470682813562030,155393901867403394
%N A232371 Number of nX3 0..3 arrays with every 0 next to a 1, every 1 next to a 2 and every 2 next to a 3 horizontally, diagonally or antidiagonally, and no adjacent values equal.
%C A232371 Column 3 of A232376
%H A232371 R. H. Hardin, <a href="/A232371/b232371.txt">Table of n, a(n) for n = 1..210</a>
%F A232371 Empirical: a(n) = 4*a(n-1) +17*a(n-2) +74*a(n-3) +170*a(n-4) +1012*a(n-5) +2868*a(n-6) +3592*a(n-7) +4816*a(n-8) +5356*a(n-9) +6245*a(n-10) +4504*a(n-11) +2633*a(n-12) +954*a(n-13) +756*a(n-14) +216*a(n-15)
%e A232371 Some solutions for n=5
%e A232371 ..0..3..2....2..3..0....3..0..3....3..2..0....1..0..1....3..2..1....2..3..2
%e A232371 ..2..1..2....2..1..0....3..2..1....0..1..3....3..2..3....3..2..3....2..0..2
%e A232371 ..0..1..0....0..1..0....3..2..3....2..1..0....1..0..1....3..0..1....3..0..1
%e A232371 ..0..1..0....2..3..2....1..0..3....0..3..0....3..0..3....3..0..1....1..2..3
%e A232371 ..2..3..0....0..1..0....3..2..1....0..1..2....3..2..3....3..2..1....1..2..1
%K A232371 nonn
%O A232371 1,1
%A A232371 _R. H. Hardin_, Nov 23 2013