A147109 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 1000-1000-1111-0010 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 9, 9, 33, 33, 105, 105, 733, 733, 10341, 10341, 272153, 272153, 6151437, 6151437

Offset

1,9

Links

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

Example

Maximal 9 X 9 example
.0.0.0.1.0.1.0.0.0
.0.0.0.1.0.1.0.0.0
.1.1.1.1.0.1.1.1.1
.0.1.0.0.0.0.0.1.0
.0.0.0.0.0.0.0.0.0
.0.1.0.0.0.0.0.1.0
.1.1.1.1.0.1.1.1.1
.0.0.0.1.0.1.0.0.0
.0.0.0.1.0.1.0.0.0

Crossrefs

Sequence in context: A146173 A146190 A147125 * A147117 A147263 A146234

Adjacent sequences: A147106 A147107 A147108 * A147110 A147111 A147112

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved