A206534 Number of (n+1) X (n+1) 0..2 arrays with the number of clockwise edge increases in 2 X 2 subblocks nondecreasing, and counterclockwise edge increases nonincreasing, rightwards and downwards.

81, 2577, 141759, 22647363, 9567269487, 10370489275269, 28770371143057311, 203028344528664369537, 3648979640901069855030843

Offset

1,1

Comments

Diagonal of A206542.

Links

Table of n, a(n) for n=1..9.

Example

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

Crossrefs

Sequence in context: A237473 A282995 A295274 * A231859 A210128 A297084

Adjacent sequences: A206531 A206532 A206533 * A206535 A206536 A206537

Keyword

nonn

Author

R. H. Hardin, Feb 09 2012

Status

approved