A183735 1/16 the number of (n+1) X 7 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.

1814815, 667017027, 211915469907, 85938883577009, 45102927396897679

Offset

1,1

Comments

Column 6 of A183738.

Links

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

Example

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

Crossrefs

Sequence in context: A249196 A137819 A145537 * A147525 A205412 A249211

Adjacent sequences: A183732 A183733 A183734 * A183736 A183737 A183738

Keyword

nonn

Author

R. H. Hardin, Jan 06 2011

Status

approved