A183722 1/12 the number of (n+1) X 3 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.

1, 2, 29, 388, 4170, 41423, 388998, 3528126, 31206553, 270945278, 2318825000, 19619049541, 164448364546, 1367755750914, 11301610770163, 92861669073522, 759320826126174, 6182626278886591, 50153160109476104, 405492870969390486

Offset

1,2

Comments

Column 2 of A183729.

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n)=14*a(n-1)-36*a(n-2)-115*a(n-3)+125*a(n-4)+164*a(n-5)-155*a(n-6)-29*a(n-7)+34*a(n-8)+a(n-9)-2*a(n-10).

Example

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

Crossrefs

Sequence in context: A198698 A094940 A152274 * A104535 A264175 A187362

Adjacent sequences: A183719 A183720 A183721 * A183723 A183724 A183725

Keyword

nonn

Author

R. H. Hardin, Jan 06 2011

Status

approved