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A210817
Number of (n+1)X(n+1) 0..3 symmetric matrices containing all values 0..3 with every 2X2 subblock having one or three distinct values, and new values 0..3 introduced in lower triangle row major order
0
0, 14, 784, 81546, 19331276, 10875523234, 14610137114552, 46893872347639870, 359629516042061730940, 6589801210361833609789898
OFFSET
1,2
EXAMPLE
Some solutions for n=3
..0..1..2..3....0..1..0..3....0..1..2..3....0..1..3..2....0..1..2..1
..1..2..3..1....1..2..2..3....1..2..0..0....1..2..1..2....1..2..3..3
..2..3..0..1....0..2..2..0....2..0..1..3....3..1..3..3....2..3..0..1
..3..1..1..3....3..3..0..3....3..0..3..0....2..2..3..3....1..3..1..3
CROSSREFS
Sequence in context: A203750 A232158 A208254 * A042519 A050983 A360612
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 27 2012
STATUS
approved