A221765 Number of nX4 arrays of occupancy after each element moves to some horizontal or vertical neighbor, without 2-loops or left turns

0, 8, 92, 1042, 12177, 141177, 1635606, 18947791, 219496141, 2542689904, 29455065560, 341214041090, 3952701351600, 45789006180212, 530430492884742, 6144630449883102, 71180832625348986, 824575377747524532

Offset

1,2

Comments

Column 4 of A221768

Links

R. H. Hardin, Table of n, a(n) for n = 1..41

Example

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

Crossrefs

Sequence in context: A280159 A155615 A322650 * A292842 A133271 A180903

Adjacent sequences: A221762 A221763 A221764 * A221766 A221767 A221768

Keyword

nonn

Author

R. H. Hardin Jan 25 2013

Status

approved