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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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Row 3 of A187670 LINKS 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 Adjacent sequences:  A187669 A187670 A187671 * A187673 A187674 A187675 KEYWORD nonn AUTHOR R. H. Hardin Mar 12 2011 STATUS approved

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Last modified July 6 15:57 EDT 2022. Contains 355111 sequences. (Running on oeis4.)