A146663 Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 1100-0111-0001 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 3, 9, 9, 23, 23, 67, 67, 379, 379, 2563, 2563, 18843, 18843

Offset

1,11

Links

Table of n, a(n) for n=1..24.

Example

Maximal 11 X 11 example
.0.0.1.1.0.0.0.1.1.0.0
.0.0.0.1.0.0.0.1.0.0.0
.1.0.0.1.1.0.1.1.0.0.1
.1.1.1.0.1.0.1.0.1.1.1
.0.0.1.1.0.0.0.1.1.0.0
.0.0.0.0.0.0.0.0.0.0.0
.0.0.1.1.0.0.0.1.1.0.0
.1.1.1.0.1.0.1.0.1.1.1
.1.0.0.1.1.0.1.1.0.0.1
.0.0.0.1.0.0.0.1.0.0.0
.0.0.1.1.0.0.0.1.1.0.0

Crossrefs

Sequence in context: A147128 A147214 A146820 * A146394 A147510 A146474

Adjacent sequences: A146660 A146661 A146662 * A146664 A146665 A146666

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved