A147106 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1000-1000-1100-0111 pattern in any orientation.

1, 1, 1, 1, 3, 7, 15, 37, 181, 733, 3563, 18321, 120179, 876663, 8507491, 85942209, 1181855975

Offset

1,5

Links

Table of n, a(n) for n=1..17.

Example

Maximal 8 X 8 example
.1.0.0.0.1.1.1.0
.1.0.0.0.0.0.1.1
.1.1.0.0.0.0.0.1
.0.1.1.1.0.0.0.1
.1.0.0.0.1.1.1.0
.1.0.0.0.0.0.1.1
.1.1.0.0.0.0.0.1
.0.1.1.1.0.0.0.1

Crossrefs

Sequence in context: A317881 A018020 A192472 * A078161 A216616 A230958

Adjacent sequences: A147103 A147104 A147105 * A147107 A147108 A147109

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved