A205738 Number of 3X(n+1) 0..2 arrays with every 2 X 2 subblock having the same number of clockwise edge increases as its horizontal neighbors and no 2 X 2 subblock having the same number of counterclockwise edge increases as its vertical neighbors.

360, 978, 3888, 17532, 80916, 376314, 1756446, 8212662, 38432652, 179925948, 842504430, 3945403368, 18476947170, 86532335682, 405257580870, 1897955537136, 8888775949212, 41629230515718, 194964278279712, 913086294849486

Offset

1,1

Comments

Row 2 of A205736.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 6*a(n-1) -2*a(n-2) -21*a(n-3) +a(n-4) +25*a(n-5) +14*a(n-6) -4*a(n-8) -2*a(n-9) for n>13.

Example

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

Crossrefs

Sequence in context: A056502 A056492 A158308 * A112536 A140801 A236059

Adjacent sequences: A205735 A205736 A205737 * A205739 A205740 A205741

Keyword

nonn

Author

R. H. Hardin, Jan 30 2012

Status

approved