A221422 Number of 4Xn arrays of occupancy after each element stays put or moves to some horizontal or antidiagonal neighbor, with every occupancy equal to zero or two

0, 16, 150, 1766, 17792, 193809, 2026142, 21225843, 221800513, 2315560756, 24158793461, 251974356335, 2627599071035, 27398017417265, 285664044010997, 2978372739958617, 31052414113756762, 323748492991437021

Offset

1,2

Comments

Row 4 of A221419

Links

R. H. Hardin, Table of n, a(n) for n = 1..33

Example

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

Crossrefs

Sequence in context: A000486 A223069 A006420 * A049351 A240424 A341391

Adjacent sequences: A221419 A221420 A221421 * A221423 A221424 A221425

Keyword

nonn

Author

R. H. Hardin Jan 15 2013

Status

approved