A147211 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 1100-0111-0011 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 17, 17, 57, 57, 405, 405, 4805, 4805, 131407, 131407, 3796773, 3796773, 159419173, 159419173

Offset

1,9

Links

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

Example

Maximal 9 X 9 example
.0.0.0.0.0.0.0.0.0
.1.1.0.0.0.0.0.1.1
.1.1.1.0.0.0.1.1.1
.0.0.1.1.0.1.1.0.0
.0.0.0.0.0.0.0.0.0
.0.0.1.1.0.1.1.0.0
.1.1.1.0.0.0.1.1.1
.1.1.0.0.0.0.0.1.1
.0.0.0.0.0.0.0.0.0

Crossrefs

Sequence in context: A146439 A146785 A146572 * A147241 A146580 A146455

Adjacent sequences: A147208 A147209 A147210 * A147212 A147213 A147214

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved