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A184099 T(n,k)=Number of nXk toroidal 0..2 arrays with each element having the sum of its vertical neighbors equal to the sum of its horizontal neighbors 2

%I

%S 3,3,3,3,9,3,3,3,3,3,3,9,87,9,3,3,3,3,3,3,3,3,9,3,361,3,9,3,3,3,87,3,

%T 3,87,3,3,3,9,3,9,1383,9,3,9,3,3,3,3,3,3,3,3,3,3,3,3,9,87,361,3,7569,

%U 3,361,87,9,3,3,3,3,3,3,3,3,3,3,3,3,3,3,9,3,9,3,9,20247,9,3,9,3,9,3,3,3,87,3

%N T(n,k)=Number of nXk toroidal 0..2 arrays with each element having the sum of its vertical neighbors equal to the sum of its horizontal neighbors

%C Number of solutions in 0..2 of a 1-d velocity-one wave equation utt=uxx on a periodic grid

%C Table starts

%C .3.3..3...3....3....3.....3......3......3.......3.3....3.3.....3....3...3.3..3

%C .3.9..3...9....3....9.....3......9......3.......9.3....9.3.....9....3...9.3..9

%C .3.3.87...3....3...87.....3......3.....87.......3.3...87.3.....3...87...3.3.87

%C .3.9..3.361....3....9.....3....361......3.......9.3..361.3.....9....3.361.3..9

%C .3.3..3...3.1383....3.....3......3......3....1383.3....3.3.....3.1383...3.3

%C .3.9.87...9....3.7569.....3......9.....87.......9.3.7569.3.....9...87...9

%C .3.3..3...3....3....3.20247......3......3.......3.3....3.3.20247....3

%C .3.9..3.361....3....9.....3.126025......3.......9.3..361.3.....9

%C .3.3.87...3....3...87.....3......3.299463.......3.3...87.3

%C .3.9..3...9.1383....9.....3......9......3.1912689.3....9

%H R. H. Hardin, <a href="/A184099/b184099.txt">Table of n, a(n) for n = 1..220</a>

%e Some solutions for 9X3

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

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

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

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

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

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

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

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

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

%K nonn,tabl

%O 1,1

%A _R. H. Hardin_ Jan 09 2011

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Last modified October 25 01:39 EDT 2020. Contains 338010 sequences. (Running on oeis4.)