A146186 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 110-111-100 pattern in any orientation.

1, 1, 1, 1, 1, 3, 17, 39, 67, 157, 683, 2593, 13101, 70047, 421791, 2622253, 19003451, 153761107, 1499143675, 15781975001, 199989123849, 2755107112873

Offset

1,6

Links

Table of n, a(n) for n=1..22.

Example

Maximal 8 X 8 example
.0.1.0.0.0.1.1.0
.1.1.0.0.0.1.1.1
.1.1.1.0.0.1.0.0
.0.0.0.0.0.0.0.0
.0.0.0.0.0.0.0.0
.0.0.1.0.0.1.1.1
.1.1.1.0.0.0.1.1
.0.1.1.0.0.0.1.0

Crossrefs

Sequence in context: A097938 A354475 A073162 * A179783 A196781 A298232

Adjacent sequences: A146183 A146184 A146185 * A146187 A146188 A146189

Keyword

nonn

Author

R. H. Hardin, Oct 27 2008

Status

approved