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A210834
Number of (n+1) X (n+1) 0..3 symmetric matrices with every 2 X 2 subblock having one, two or four distinct values, and new values 0..3 introduced in lower triangle row major order.
0
4, 51, 1675, 125483, 20178747, 6756016331, 4647730539387, 6537458079419739, 18773661532321526331, 110047493954215211056859
OFFSET
1,1
EXAMPLE
Some solutions for n=3
..0..1..2..3....0..1..2..3....0..1..1..3....0..1..0..0....0..1..1..1
..1..0..3..3....1..1..1..0....1..1..1..3....1..0..0..2....1..1..1..1
..2..3..0..0....2..1..2..3....1..1..2..0....0..0..1..3....1..1..1..1
..3..3..0..0....3..0..3..2....3..3..0..0....0..2..3..1....1..1..1..0
CROSSREFS
Sequence in context: A300732 A220282 A235326 * A287231 A289708 A000516
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 27 2012
STATUS
approved