A146820 Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 1000-1110-0111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 3, 9, 9, 23, 23, 59, 59, 317, 317, 2143, 2143, 14651

Offset

1,11

Links

Table of n, a(n) for n=1..23.

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
.1.1.1.0.1.0.1.0.1.1.1
.0.1.1.1.0.0.0.1.1.1.0
.0.0.0.0.0.0.0.0.0.0.0
.0.1.1.1.0.0.0.1.1.1.0
.1.1.1.0.1.0.1.0.1.1.1
.1.0.0.1.1.0.1.1.0.0.1
.0.0.0.1.1.0.1.1.0.0.0
.0.0.1.1.0.0.0.1.1.0.0

Crossrefs

Sequence in context: A146442 A147128 A147214 * A146663 A146394 A147510

Adjacent sequences: A146817 A146818 A146819 * A146821 A146822 A146823

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved