A146644 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 1010-1111-1000 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 17, 17, 53, 53, 329, 329, 3935, 3935, 73477, 73477, 2119711, 2119711, 76531381, 76531381

Offset

1,9

Links

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

Example

Maximal 9 X 9 example
.0.0.0.0.0.0.0.0.0
.1.0.0.0.0.0.0.0.1
.1.1.1.1.0.1.1.1.1
.1.0.1.0.0.0.1.0.1
.0.0.0.0.0.0.0.0.0
.1.0.1.0.0.0.1.0.1
.1.1.1.1.0.1.1.1.1
.1.0.0.0.0.0.0.0.1
.0.0.0.0.0.0.0.0.0

Crossrefs

Sequence in context: A146463 A146841 A147180 * A146612 A146849 A146716

Adjacent sequences: A146641 A146642 A146643 * A146645 A146646 A146647

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved