A147288 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1100-0111-0001-0001 pattern in any orientation.

1, 1, 1, 1, 5, 13, 29, 101, 617, 3357, 20865, 140793, 1290919, 15614005, 229745285, 3898534669

Offset

1,5

Links

Table of n, a(n) for n=1..16.

Example

Maximal 8 X 8 example
.1.0.0.1.1.1.0.0
.1.0.0.0.0.1.0.0
.1.1.1.0.0.1.1.0
.0.0.1.1.0.0.1.0
.0.1.0.0.1.1.0.0
.0.1.1.0.0.1.1.1
.0.0.1.0.0.0.0.1
.0.0.1.1.1.0.0.1

Crossrefs

Sequence in context: A147278 A268963 A147349 * A146420 A147492 A182069

Adjacent sequences: A147285 A147286 A147287 * A147289 A147290 A147291

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved