A253316 Number of 2n X 2n Takuzu grids.

1, 2, 72, 4140, 4111116, 48183195384

Offset: 0

Author

Brian Kell, Dec 30 2014

Keywords

• nonn
• more

Comments

A Takuzu grid is a 2n X 2n zero-one matrix with the following properties:

1. Every row and every column has n zeros and n ones.

2. No row or column has three consecutive zeros or three consecutive ones.

3. All rows are distinct, and all columns are distinct (but a row may be the same as a column).

Examples

			The following is a 4 X 4 Takuzu grid:
[ 0  1  1  0 ]
[ 1  0  0  1 ]
[ 0  0  1  1 ]
[ 1  1  0  0 ]
		

Links

• Wikipedia, Takuzu

Crossrefs

Cf. A058527.

Number of possible rows equals A003440.

Extensions

a(5) from Frans J. Faase, Dec 14 2015