A147149 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 1000-1100-0111-0010 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 9, 9, 33, 33, 121, 121, 1109, 1109, 21917, 21917, 638145, 638145, 19928333, 19928333

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
.0.0.1.1.0.1.1.0.0
.1.1.1.0.0.0.1.1.1
.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
.1.1.1.0.0.0.1.1.1
.0.0.1.1.0.1.1.0.0
.0.0.0.1.0.1.0.0.0

Crossrefs

Sequence in context: A147263 A146234 A146182 * A147277 A146138 A147446

Adjacent sequences: A147146 A147147 A147148 * A147150 A147151 A147152

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved