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
Keywords
Examples
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...
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).
Comments