A146236 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 110-111-001 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 9, 17, 33, 89, 333, 849, 5379, 20923, 147329, 704405, 5858399, 36340527, 403495741, 3132269377, 47135996775, 474369570793, 8861603100211, 114644138972971

Offset

1,8

Links

Table of n, a(n) for n=1..25.

Example

Maximal 8 X 8 example
.0.0.0.0.1.1.0.0
.0.0.0.0.1.1.0.0
.0.0.0.1.1.0.1.1
.0.0.1.0.0.1.1.1
.1.1.1.0.0.1.0.0
.1.1.0.1.1.0.0.0
.0.0.1.1.0.0.0.0
.0.0.1.1.0.0.0.0

Crossrefs

Sequence in context: A127193 A262453 A197344 * A147279 A173788 A097478

Adjacent sequences: A146233 A146234 A146235 * A146237 A146238 A146239

Keyword

nonn

Author

R. H. Hardin

Status

approved