A147138 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1000-1001-1111 pattern in any orientation.

1, 1, 1, 1, 9, 17, 47, 169, 947, 4301, 28001, 189379, 2123749, 21459731, 367346875, 5385601539

Offset

1,5

Links

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

Example

Maximal 8 X 8 example
.0.0.0.0.1.1.1.1
.1.0.0.0.1.0.0.1
.1.0.0.1.0.0.0.1
.1.1.1.1.0.0.0.0
.0.0.0.0.1.1.1.1
.1.0.0.0.1.0.0.1
.1.0.0.1.0.0.0.1
.1.1.1.1.0.0.0.0

Crossrefs

Sequence in context: A146625 A318755 A146576 * A282764 A319018 A101304

Adjacent sequences: A147135 A147136 A147137 * A147139 A147140 A147141

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved