A147125 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 1000-1000-1111-1000 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 9, 9, 33, 33, 105, 105, 641, 641, 8787, 8787, 211111, 211111, 4653287

Offset

1,9

Links

Table of n, a(n) for n=1..21.

Example

Maximal 9 X 9 example
.1.0.0.0.0.0.0.0.1
.1.0.0.0.0.0.0.0.1
.1.1.1.1.0.1.1.1.1
.1.0.0.0.0.0.0.0.1
.0.0.0.0.0.0.0.0.0
.1.0.0.0.0.0.0.0.1
.1.1.1.1.0.1.1.1.1
.1.0.0.0.0.0.0.0.1
.1.0.0.0.0.0.0.0.1

Crossrefs

Sequence in context: A146258 A146173 A146190 * A147109 A147117 A147263

Adjacent sequences: A147122 A147123 A147124 * A147126 A147127 A147128

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved