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URL: https://oeis.org/A187672

⇱ A187672 - OEIS

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A187672
Number of 4X4 0..n arrays with each 2X2 subblock nonsingular and the array of 2X2 subblock determinants symmetric about the diagonal and antidiagonal.
0
112, 11282, 174292, 1549398, 6839146, 32368980, 88344978, 268011840
OFFSET
1,1
COMMENTS
Row 3 of A187670
EXAMPLE
Some n=3 solutions for 4X4
..0..1..1..2....0..2..2..2....0..2..2..3....0..2..2..2....2..1..1..2
..2..0..2..3....2..0..3..0....2..0..2..1....3..0..3..1....1..0..2..2
..3..1..0..1....2..3..0..2....0..2..0..2....0..2..0..2....2..2..0..1
..1..0..2..1....2..0..2..1....2..2..2..1....2..1..3..3....3..2..1..3
CROSSREFS
Sequence in context: A203788 A180027 A240229 * A049217 A206310 A331670
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 12 2011
STATUS
approved