A221554 Number of 4Xn arrays of occupancy after each element moves to some horizontal, vertical or antidiagonal neighbor, without move-in move-out left turns

4, 494, 47976, 4107189, 354947070, 30632388919, 2643033185667, 228021702640082, 19671424819923462

Offset

1,1

Comments

Row 4 of A221551

Links

Table of n, a(n) for n=1..9.

Example

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

Crossrefs

Sequence in context: A024058 A357536 A330579 * A210310 A324155 A350968

Adjacent sequences: A221551 A221552 A221553 * A221555 A221556 A221557

Keyword

nonn

Author

R. H. Hardin Jan 19 2013

Status

approved