A147146 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1000-1100-0110-0011 pattern in any orientation.

1, 1, 1, 1, 3, 9, 19, 67, 271, 1339, 7503, 48863, 386667, 3842993, 45897369, 657696677

Offset

1,5

Links

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

Example

Maximal 8 X 8 example
.0.0.1.1.0.0.0.0
.0.1.1.0.0.0.0.1
.1.1.0.0.0.0.1.1
.1.0.1.1.0.1.1.0
.0.1.1.0.1.1.0.1
.1.1.0.0.0.0.1.1
.1.0.0.0.0.1.1.0
.0.0.0.0.1.1.0.0

Crossrefs

Sequence in context: A146605 A147070 A130586 * A146066 A164283 A375231

Adjacent sequences: A147143 A147144 A147145 * A147147 A147148 A147149

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved