A213412 Half the number of n X n binary arrays with no 3X3 submatrix formed with any three rows and columns equal to J-I

1, 8, 253, 28952, 10142461, 9107867048, 18095156337973

Offset

1,2

Comments

Diagonal of A213418

Links

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

Example

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

Crossrefs

Sequence in context: A301401 A162132 A297051 * A226428 A277421 A171612

Adjacent sequences: A213409 A213410 A213411 * A213413 A213414 A213415

Keyword

nonn

Author

R. H. Hardin and N. J. A. Sloane Jun 10 2012

Status

approved