A221893 Number of 4Xn arrays of occupancy after each element moves to some horizontal, diagonal or antidiagonal neighbor, without 2-loops or left turns

0, 0, 90, 4137, 154458, 5488703, 201212852, 7816225089, 303242246539, 11670544747194, 449384417173902, 17313378667903125, 666942058278936822, 25692119785626315240, 989734547009551775051

Offset

1,3

Comments

Row 4 of A221890

Links

Table of n, a(n) for n=1..15.

Example

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

Crossrefs

Sequence in context: A017806 A035740 A017753 * A197194 A281580 A369144

Adjacent sequences: A221890 A221891 A221892 * A221894 A221895 A221896

Keyword

nonn

Author

R. H. Hardin Jan 30 2013

Status

approved