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

112, 11282, 174292, 1549398, 6839146, 32368980, 88344978, 268011840

Offset

1,1

Comments

Row 3 of A187670

Links

Table of n, a(n) for n=1..8.

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