A146659 Number of n X n binary arrays symmetric under horizontal reflection with all ones connected only in a 1100-0111-0001 pattern in any orientation.

1, 1, 1, 1, 1, 1, 19, 31, 777, 1691, 27963, 75639, 2292715, 7576569, 826036495, 3496134625, 778953197867, 4202373389229, 1495755903085789, 10132125701626967, 6580332072056181975, 55813749926331270805

Offset

1,7

Links

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

Example

Maximal 8 X 8 example
.0.1.1.0.0.1.1.0
.0.1.0.0.0.0.1.0
.1.1.0.0.0.0.1.1
.1.0.0.0.0.0.0.1
.0.0.1.0.0.1.0.0
.0.1.1.0.0.1.1.0
.0.1.0.0.0.0.1.0
.1.1.0.0.0.0.1.1

Crossrefs

Sequence in context: A147240 A147210 A146816 * A160220 A133151 A184750

Adjacent sequences: A146656 A146657 A146658 * A146660 A146661 A146662

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved