A146237 Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 110-111-001 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 5, 5, 17, 17, 37, 37, 167, 167, 1407, 1407, 11143, 11143, 90213, 90213, 1212859

Offset

1,11

Links

Table of n, a(n) for n=1..25.

Example

Maximal 11 X 11 example
.0.0.1.1.0.0.0.1.1.0.0
.0.0.0.1.1.0.1.1.0.0.0
.1.0.0.1.1.0.1.1.0.0.1
.1.1.1.0.0.0.0.0.1.1.1
.0.1.1.0.0.0.0.0.1.1.0
.0.0.0.0.0.0.0.0.0.0.0
.0.1.1.0.0.0.0.0.1.1.0
.1.1.1.0.0.0.0.0.1.1.1
.1.0.0.1.1.0.1.1.0.0.1
.0.0.0.1.1.0.1.1.0.0.0
.0.0.1.1.0.0.0.1.1.0.0

Crossrefs

Sequence in context: A146876 A147206 A146852 * A282501 A147167 A146647

Adjacent sequences: A146234 A146235 A146236 * A146238 A146239 A146240

Keyword

nonn

Author

R. H. Hardin

Status

approved