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A187530 Number of 4X4 0..n arrays with each 2X2 subblock determinant nonzero and the array of 2X2 subblock determinants symmetric under 90 degree rotation 0
104, 3790, 35026, 220802, 727842, 2327574, 5366230, 13768228, 28531154, 54987216, 90945478 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Row 3 of A187528
LINKS
EXAMPLE
Some solutions for 4X4
..3..1..2..1....3..3..1..3....3..0..3..1....2..3..3..3....2..1..0..1
..1..0..1..0....2..3..0..3....1..2..0..2....1..0..1..0....2..0..2..1
..0..1..0..1....1..0..1..0....3..0..3..3....3..3..0..3....0..1..0..1
..1..0..1..0....0..3..0..3....0..2..0..2....1..0..1..2....2..3..2..2
CROSSREFS
Sequence in context: A217773 A298460 A299553 * A185741 A299333 A007267
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 10 2011
STATUS
approved

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Last modified June 16 16:46 EDT 2024. Contains 373432 sequences. (Running on oeis4.)