A146415 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 1000-1111-1000 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 18, 9, 192, 29, 1571, 137, 16589, 1117, 263101, 13601, 7736259, 257342, 336101213, 6436423, 19847949792, 229848194

Offset

1,9

Links

Table of n, a(n) for n=1..24.

Example

Maximal 9 X 9 example
.0.1.0.1.1.1.0.1.0
.0.1.0.0.1.0.0.1.0
.0.1.0.0.1.0.0.1.0
.1.1.1.0.1.0.1.1.1
.0.0.0.0.0.0.0.0.0
.1.1.1.0.1.0.1.1.1
.0.1.0.0.1.0.0.1.0
.0.1.0.0.1.0.0.1.0
.0.1.0.1.1.1.0.1.0

Crossrefs

Sequence in context: A146676 A147438 A033965 * A089517 A290345 A035616

Adjacent sequences: A146412 A146413 A146414 * A146416 A146417 A146418

Keyword

nonn

Author

R. H. Hardin

Status

approved