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%I #5 Dec 18 2015 18:18:05
%S 1,2,20,464,22564,2472584,603871080,327862785884,395850912855384,
%T 1063574508841830552,6358546221961060404292,84578736940287879637237736
%N Number of n X n 0..2 symmetric matrices with every element equal to zero, one or three horizontal and vertical neighbors, and new values 0..2 introduced in lower triangle row major order
%e Some solutions for n=4
%e ..0..1..2..1....0..1..2..1....0..1..2..2....0..1..0..1....0..1..0..2
%e ..1..0..2..0....1..0..1..0....1..0..1..0....1..0..2..1....1..0..1..0
%e ..2..2..0..1....2..1..0..2....2..1..0..2....0..2..1..0....0..1..2..0
%e ..1..0..1..2....1..0..2..1....2..0..2..0....1..1..0..1....2..0..0..1
%K nonn
%O 1,2
%A _R. H. Hardin_ Mar 29 2012
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