A183773 Half the number of (n+1) X (n+1) binary arrays with no 2 X 2 subblock having exactly 2 ones.

5, 47, 730, 21935, 1146964, 112439612, 19815396763, 6453534773135, 3829236554668274, 4179465974043040784, 8354373579461755560239, 30686484702497770109712496, 206872691877488790419478443459

Offset

1,1

Links

Table of n, a(n) for n=1..13.

Example

Some solutions with a(1,1)=0 for 3X3
..0..1..0....0..0..0....0..0..1....0..0..0....0..0..0....0..1..0....0..0..0
..0..0..0....1..0..0....0..0..0....0..0..1....0..0..0....0..0..0....0..1..0
..0..0..0....0..0..0....1..0..0....0..1..1....1..0..1....0..0..1....1..1..1

Crossrefs

Diagonal of A183782.

Sequence in context: A254530 A086555 A246040 * A247982 A222078 A061572

Adjacent sequences: A183770 A183771 A183772 * A183774 A183775 A183776

Keyword

nonn

Author

R. H. Hardin, Jan 07 2011

Status

approved