A208484 Number of (n+1) X (n+1) 0..3 arrays with the number of clockwise edge increases in every 2 X 2 subblock equal to the number of counterclockwise edge increases.

152, 33416, 43689232, 343092183768, 16261866249456960, 4664832940178290442768, 8112174131718066295245481744, 85615997981426512072932676873435656

Offset

1,1

Comments

Diagonal of A208492.

Links

Table of n, a(n) for n=1..8.

Example

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

Crossrefs

Sequence in context: A229418 A035823 A265861 * A335091 A323319 A157881

Adjacent sequences: A208481 A208482 A208483 * A208485 A208486 A208487

Keyword

nonn

Author

R. H. Hardin, Feb 27 2012

Status

approved