A207141 Number of (n+1)X(n+1) 0..2 arrays with every 2X2 subblock having nonzero determinant and commuting with every horizontal or vertical neighbor

50, 48, 157, 190, 622, 754, 2482, 3010, 9922, 12034, 39682, 48130, 158722, 192514, 634882, 770050, 2539522, 3080194, 10158082, 12320770, 40632322, 49283074, 162529282, 197132290

Offset

1,1

Comments

Diagonal of A207149

Links

Table of n, a(n) for n=1..24.

Example

Some solutions for n=4
..2..1..0..1..0....1..1..0..1..0....2..2..0..1..0....0..2..0..1..0
..1..0..1..0..1....1..0..1..0..1....1..0..2..0..1....1..0..2..0..1
..0..1..0..1..0....0..1..0..1..0....0..1..0..2..0....0..1..0..2..0
..2..0..1..0..1....1..0..1..0..1....1..0..1..0..2....1..0..1..0..2
..0..2..0..1..2....0..1..0..1..0....0..1..0..1..1....0..1..0..1..2

Crossrefs

Sequence in context: A244277 A248688 A291495 * A256958 A165871 A171652

Adjacent sequences: A207138 A207139 A207140 * A207142 A207143 A207144

Keyword

nonn

Author

R. H. Hardin Feb 15 2012

Status

approved