A183720 1/12 the number of (n+1) X (n+1) 0..5 arrays with every 2 X 2 subblock strictly increasing clockwise or counterclockwise with one decrease, and at least two adjacent blocks having the same increasing direction.

0, 2, 124, 14886, 3723606, 2740758406, 5585215240568, 33429749952933774, 583208471844467888006

Offset

1,2

Comments

Diagonal of A183729.

Links

Table of n, a(n) for n=1..9.

Example

Some solutions with the first block increasing clockwise for 3 X 3:
..5..0..1....1..2..3....4..5..4....2..3..2....0..1..2....5..0..5....3..4..3
..4..3..2....0..5..4....3..0..3....1..4..1....5..4..3....4..1..4....2..5..2
..5..0..1....1..2..3....2..1..2....0..5..0....0..1..2....3..2..3....1..0..1
...
...R..R.......R..R.......R..L.......R..L.......R..R.......R..L.......R..L...
...L..L.......L..L.......R..L.......R..L.......L..L.......R..L.......R..L...

Crossrefs

Sequence in context: A088055 A065705 A012870 * A042921 A123006 A028481

Adjacent sequences: A183717 A183718 A183719 * A183721 A183722 A183723

Keyword

nonn

Author

R. H. Hardin, Jan 06 2011

Status

approved