A221771 - OEIS

A221771

Number of nX4 arrays of occupancy after each element stays put or moves to some horizontal or vertical neighbor, without move-in move-out left turns

21, 2127, 225873, 23965217, 2541024755, 269350655878, 28548644230368, 3025789208683568, 320691065003362685, 33988597488799369041, 3602292346906129492849

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Column 4 of A221773

LINKS

Table of n, a(n) for n=1..11.

EXAMPLE

Some solutions for n=3

..0..1..0..2....1..1..0..0....0..3..0..0....0..1..1..2....0..1..0..1

..1..1..0..1....1..1..2..2....1..3..0..1....1..2..1..0....0..2..1..2

..0..3..3..0....0..0..4..0....1..1..1..1....1..1..2..0....1..3..0..1

CROSSREFS

Sequence in context: A300577 A304643 A153848 * A007593 A219104 A219983

Adjacent sequences: A221768 A221769 A221770 * A221772 A221773 A221774

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 25 2013

STATUS

approved