A147026 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 01000-11111-01000 pattern in any orientation.

1, 1, 1, 1, 1, 9, 17, 35, 145, 589, 2723, 16121, 110705, 888953, 8435682, 98480917, 1294018001, 21003172843

Offset

1,6

Links

Table of n, a(n) for n=1..18.

Example

Maximal 8 X 8 example
.0.1.0.0.1.0.0.0
.0.1.0.1.1.1.1.1
.0.1.0.0.1.0.0.0
.1.1.1.0.0.0.1.0
.0.1.0.0.0.1.1.1
.0.0.0.1.0.0.1.0
.1.1.1.1.1.0.1.0
.0.0.0.1.0.0.1.0

Crossrefs

Sequence in context: A147279 A173788 A097478 * A055393 A147082 A145941

Adjacent sequences: A147023 A147024 A147025 * A147027 A147028 A147029

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved