A187706 Number of 3X3 0..n arrays with each 2X2 subblock off diagonal and antidiagonal nonsingular and the array of 2X2 subblock determinants antisymmetric about the diagonal and antidiagonal

128, 1489, 8272, 31461, 93476, 235773, 524284, 1062857, 1999212, 3541677, 5967404, 9648841, 15048584, 22766353, 33534080, 48248321, 67983232, 94042589, 127929948, 171449249, 226655576, 295941137, 382036240, 488090685, 617595596, 774557293

Offset

1,1

Comments

Row 2 of A187705

Links

R. H. Hardin, Table of n, a(n) for n = 1..33

Example

Some n=3 solutions for 3X3
..3..0..0....2..0..3....0..0..1....3..1..1....0..0..3....2..0..0....2..0..0
..2..0..3....2..0..0....3..0..1....0..0..0....0..0..3....1..0..0....0..0..0
..1..0..0....1..0..0....2..0..3....3..2..1....3..0..1....0..0..3....0..2..2

Crossrefs

Sequence in context: A070055 A247930 A200842 * A202961 A239540 A327772

Adjacent sequences: A187703 A187704 A187705 * A187707 A187708 A187709

Keyword

nonn

Author

R. H. Hardin Mar 12 2011

Status

approved