A146388 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 0110-1111 pattern in any orientation.

1, 1, 1, 1, 9, 20, 73, 328, 1655, 10746, 103583, 974458, 13360226, 192146495, 4002035013, 89158887545, 2840078369454

Offset

1,5

Links

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

Example

Maximal 8 X 8 example
.0.1.1.0.1.1.1.1
.1.1.1.1.0.1.1.0
.0.0.0.0.0.0.0.0
.0.1.1.0.1.1.1.1
.1.1.1.1.0.1.1.0
.0.0.0.0.0.0.0.0
.0.1.1.0.1.1.1.1
.1.1.1.1.0.1.1.0

Crossrefs

Sequence in context: A344818 A341529 A013573 * A230833 A321723 A282763

Adjacent sequences: A146385 A146386 A146387 * A146389 A146390 A146391

Keyword

nonn

Author

R. H. Hardin

Status

approved