A205936 Number of (n+1) X (n+1) 0..3 arrays with no 2 X 2 subblock having the number of clockwise edge increases equal to the number of counterclockwise edge increases in its adjacent leftward or upward neighbors.

256, 11028, 754704, 70027468, 8605131924, 1498787263308, 451135236949228

Offset

1,1

Comments

Diagonal of A205944.

Links

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

Example

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

Crossrefs

Sequence in context: A224393 A224026 A237966 * A264496 A224967 A205652

Adjacent sequences: A205933 A205934 A205935 * A205937 A205938 A205939

Keyword

nonn

Author

R. H. Hardin, Feb 01 2012

Status

approved