A205634 Number of (n+1)X(n+1) 0..3 arrays with every 2 X 2 subblock having the number of clockwise edge increases equal to the number of counterclockwise edge increases in its adjacent leftward and upward neighbors.

256, 28724, 8381936, 11786800328, 101664965477840, 4561749663096542724, 995980221935339574016820

Offset

1,1

Comments

Diagonal of A205642.

Links

Table of n, a(n) for n=1..7.

Example

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

Crossrefs

Sequence in context: A205019 A017212 A181243 * A269292 A205362 A206101

Adjacent sequences: A205631 A205632 A205633 * A205635 A205636 A205637

Keyword

nonn

Author

R. H. Hardin, Jan 29 2012

Status

approved