A221739 Number of 4Xn arrays of occupancy after each element stays put or moves to some horizontal or antidiagonal neighbor, without move-in move-out left turns

1, 489, 54888, 5962648, 635754537, 67528875354, 7163909304549, 759566587771238, 80515544879207321, 8533986434770695295, 904498107089443489067, 95864312683893293318311, 10160235943126188410457063

Offset

1,2

Comments

Row 4 of A221736

Links

Table of n, a(n) for n=1..13.

Example

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

Crossrefs

Sequence in context: A251676 A230005 A221940 * A068751 A172951 A287329

Adjacent sequences: A221736 A221737 A221738 * A221740 A221741 A221742

Keyword

nonn

Author

R. H. Hardin Jan 22 2013

Status

approved