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T(n,k)=Number of nXk 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 4,3,0,1,2 for x=0,1,2,3,4
8

%I #5 Mar 31 2012 12:36:29

%S 1,1,1,2,7,2,3,12,12,3,5,31,55,31,5,8,79,242,242,79,8,13,186,1178,

%T 2117,1178,186,13,21,465,5355,17759,17759,5355,465,21,34,1131,24723,

%U 141210,249929,141210,24723,1131,34,55,2776,116440,1207249,3710070,3710070

%N T(n,k)=Number of nXk 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 4,3,0,1,2 for x=0,1,2,3,4

%C Every 0 is next to 0 4's, every 1 is next to 1 3's, every 2 is next to 2 0's, every 3 is next to 3 1's, every 4 is next to 4 2's

%C Table starts

%C ..1....1.......2.........3............5..............8................13

%C ..1....7......12........31...........79............186...............465

%C ..2...12......55.......242.........1178...........5355.............24723

%C ..3...31.....242......2117........17759.........141210...........1207249

%C ..5...79....1178.....17759.......249929........3710070..........56349129

%C ..8..186....5355....141210......3710070.......98514881........2633810897

%C .13..465...24723...1207249.....56349129.....2633810897......126615582841

%C .21.1131..116440..10193669....835898389....70009757794.....6025045947229

%C .34.2776..545287..85161702..12424253226..1862777323325...285872930194581

%C .55.6803.2548432.716691651.185170942121.49566883751088.13601246931224843

%H R. H. Hardin, <a href="/A197235/b197235.txt">Table of n, a(n) for n = 1..144</a>

%e Some solutions for n=6 k=4

%e ..0..1..3..1....0..1..3..1....0..2..0..0....0..0..2..0....0..0..2..0

%e ..0..2..1..0....0..1..1..0....0..2..0..1....0..0..1..0....2..1..3..1

%e ..2..0..2..0....2..3..1..0....0..2..1..3....0..1..3..2....0..0..1..0

%e ..1..1..3..1....0..1..1..0....1..0..2..1....2..0..1..0....0..0..0..2

%e ..3..1..1..0....0..2..3..1....3..1..0..0....1..3..1..0....2..2..0..2

%e ..1..0..0..2....0..0..1..0....1..0..0..2....0..1..0..0....0..2..0..0

%Y Column 1 is A000045

%K nonn,tabl

%O 1,4

%A _R. H. Hardin_ Oct 12 2011