A183736 1/16 the number of (n+1) X 8 0..7 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.

23204876, 21320890377, 16635894447271, 16327766532728500, 19628509753968319015

Offset

1,1

Comments

Column 7 of A183738.

Links

Table of n, a(n) for n=1..5.

Example

Some solutions with the first block increasing clockwise for 3 X 8:
..0..1..0..1..7..5..2..0....0..1..0..1..0..1..0..7....0..1..0..1..5..0..1..5
..3..2..3..2..3..4..3..5....3..2..3..2..5..4..5..6....3..2..3..2..4..3..2..4
..0..1..0..1..0..6..7..6....0..1..0..1..7..3..2..0....0..1..0..1..7..0..1..5
...
...R..L..R..L..L..R..L.......R..L..R..L..R..L..L.......R..L..R..L..R..R..L...
...L..R..L..R..R..L..R.......L..R..L..R..L..R..R.......L..R..L..R..L..L..R...

Crossrefs

Sequence in context: A114666 A157079 A321065 * A105238 A252396 A236366

Adjacent sequences: A183733 A183734 A183735 * A183737 A183738 A183739

Keyword

nonn

Author

R. H. Hardin, Jan 06 2011

Status

approved