A147274 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1000-1000-1111-0001 pattern in any orientation.

1, 1, 1, 1, 1, 5, 25, 85, 377, 1825, 10067, 61143

Offset

1,6

Links

Table of n, a(n) for n=1..12.

Example

Maximal 8 X 8 example
.0.0.0.1.0.0.1.1
.1.1.1.1.0.0.1.0
.1.0.0.0.0.0.1.0
.1.0.0.0.1.1.1.0
.0.1.1.1.0.0.0.1
.0.1.0.0.0.0.0.1
.0.1.0.0.1.1.1.1
.1.1.0.0.1.0.0.0

Crossrefs

Sequence in context: A058919 A018212 A181477 * A147034 A146460 A223840

Adjacent sequences: A147271 A147272 A147273 * A147275 A147276 A147277

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved