A147244 Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 1101-0111-0010 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 3, 9, 9, 27, 27, 87, 87, 355, 355, 2031, 2031, 15277

Offset

1,11

Links

Table of n, a(n) for n=1..23.

Example

Maximal 11 X 11 example
.0.0.0.1.1.0.1.1.0.0.0
.0.0.1.1.0.0.0.1.1.0.0
.0.1.0.1.1.0.1.1.0.1.0
.1.1.1.0.1.0.1.0.1.1.1
.1.0.1.1.0.0.0.1.1.0.1
.0.0.0.0.0.0.0.0.0.0.0
.1.0.1.1.0.0.0.1.1.0.1
.1.1.1.0.1.0.1.0.1.1.1
.0.1.0.1.1.0.1.1.0.1.0
.0.0.1.1.0.0.0.1.1.0.0
.0.0.0.1.1.0.1.1.0.0.0

Crossrefs

Sequence in context: A108411 A162436 A146788 * A146575 A373322 A100066

Adjacent sequences: A147241 A147242 A147243 * A147245 A147246 A147247

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved