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A186168 T(n,k)=1/4 the number of nXk 0..3 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors 9

%I #5 Mar 31 2012 12:36:05

%S 0,1,1,1,7,1,4,48,48,4,7,321,702,321,7,19,2175,14364,14364,2175,19,40,

%T 14748,253341,751266,253341,14748,40,97,99933,4762206,37402872,

%U 37402872,4762206,99933,97,217,677283,87054174,1899336597,5033988714,1899336597

%N T(n,k)=1/4 the number of nXk 0..3 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors

%C Table starts

%C ...0........1............1...............4.................7.................19

%C ...1........7...........48.............321..............2175..............14748

%C ...1.......48..........702...........14364............253341............4762206

%C ...4......321........14364..........751266..........37402872.........1899336597

%C ...7.....2175.......253341........37402872........5033988714.......704281652979

%C ..19....14748......4762206......1899336597......704281652979....268995986029278

%C ..40....99933.....87054174.....95752776009....96951738076992.101554003879403823

%C ..97...677283...1610684397...4840082975532.13435825601048421

%C .217..4590168..29645381115.244420512852030

%C .508.31108893.546876640548

%H R. H. Hardin, <a href="/A186168/b186168.txt">Table of n, a(n) for n = 1..84</a>

%e Some solutions for 5X4 with a(1,1)=0

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

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

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

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

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

%Y Column 1 is A006130(n-2)

%K nonn,tabl

%O 1,5

%A _R. H. Hardin_ Feb 13 2011

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Last modified April 24 19:59 EDT 2024. Contains 371963 sequences. (Running on oeis4.)