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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
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
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
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 06 2011
STATUS
approved