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 A210928 Number of n X n 0..3 symmetric matrices with every element equal to zero or one horizontal and vertical neighbors, and new values 0..3 introduced in lower triangle row major order 0

%I #5 Dec 18 2015 18:18:06

%S 1,2,55,5892,2081181,2353015360,8533282805517,99227545384370981,

%T 3699909251614783425693,442375363534050667939662012,

%U 169602369911112134429648742314656

%N Number of n X n 0..3 symmetric matrices with every element equal to zero or one horizontal and vertical neighbors, and new values 0..3 introduced in lower triangle row major order

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,2

%A _R. H. Hardin_ Mar 29 2012

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Last modified December 2 21:04 EST 2023. Contains 367526 sequences. (Running on oeis4.)