A221768 T(n,k)=Number of nXk arrays of occupancy after each element moves to some horizontal or vertical neighbor, without 2-loops or left turns

0, 0, 0, 0, 1, 0, 0, 3, 3, 0, 0, 8, 16, 8, 0, 0, 21, 92, 92, 21, 0, 0, 55, 536, 1042, 536, 55, 0, 0, 144, 3125, 12177, 12177, 3125, 144, 0, 0, 377, 18216, 141177, 296912, 141177, 18216, 377, 0, 0, 987, 106174, 1635606, 7115200, 7115200, 1635606, 106174, 987, 0, 0, 2584

Offset

1,8

Comments

Table starts

.0.....0........0..........0...........0............0.............0

.0.....1........3..........8..........21...........55...........144

.0.....3.......16.........92.........536.........3125.........18216

.0.....8.......92.......1042.......12177.......141177.......1635606

.0....21......536......12177......296912......7115200.....170234678

.0....55.....3125.....141177.....7115200....347487163...16949434757

.0...144....18216....1635606...170234678..16949434757.1685013765256

.0...377...106174...18947791..4073986651.827634377153

.0...987...618832..219496141.97465620298

.0..2584..3606823.2542689904

.0..6765.21022112

.0.17711

Links

R. H. Hardin, Table of n, a(n) for n = 1..97

Example

Some solutions for n=3 k=4
..0..1..0..1....1..2..1..0....0..1..1..1....1..1..1..1....1..1..1..1
..1..2..0..2....1..0..1..1....1..2..1..1....2..1..1..1....1..0..0..1
..1..2..1..1....1..1..2..1....1..1..1..1....1..0..1..1....1..2..2..1

Crossrefs

Column 2 is A001906(n-1)

Sequence in context: A155999 A338034 A299904 * A283071 A060523 A199041

Adjacent sequences: A221765 A221766 A221767 * A221769 A221770 A221771

Keyword

nonn,tabl

Author

R. H. Hardin Jan 25 2013

Status

approved