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%I #4 Mar 30 2012 16:49:45
%S 1,1,1,1,1,1,2,2,2,2,2,2,2,2,2,2,3,3,3,3,2,3,3,4,4,4,3,3,3,4,4,5,5,4,
%T 4,3,3,4,5,6,6,6,5,4,3,4,5,6,6,7,7,6,6,5,4,4,5,6,8,8,8,8,8,6,5,4,4,6,
%U 7,8,9,9,9,9,8,7,6,4
%N Array read by antidiagonals: T(n,k) = size of maximal subset of nodes in n X k grid such that there at least 3 edges between any pair of nodes (n >= 1, k >= 1).
%C The 1-neighborhoods of the nodes must be disjoint: i.e. this is a 1-error correcting code.
%F T(n, 1) = floor((n+2)/3), T(n, 2) = floor((n+1)/2).
%e Array begins
%e 1 1 1 2 2 2 3 3 3 4 ...
%e 1 1 2 2 3 3 4 4 5 5 ...
%e 1 2 2 3 4 4 5 6 6 7 ...
%e 2 2 3 4 5 6 6 8 8 9 ...
%e For example, T(3,4) = 3 (*'s indicate the chosen nodes):
%e o--*--o--o
%e |..|..|..|
%e o--o--o--o
%e |..|..|..|
%e *--o--o--*
%Y Main diagonal gives A085577.
%K nonn,tabl
%O 1,7
%A _N. J. A. Sloane_, Jul 08 2003
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