A146220 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 101-111-010 pattern in any orientation.

1, 1, 1, 1, 1, 1, 2, 5, 10, 17, 34, 85, 281, 955, 3256, 11436, 47842, 229549, 1285142, 7367162, 46939349, 319959201, 2574706386, 22549841306, 223885431121, 2344970886285, 27997518161136, 360114867911637, 5365975270644628

Offset

1,7

Links

Table of n, a(n) for n=1..29.

Example

Maximal 8 X 8 example
.0.0.0.1.0.1.0.0
.0.0.0.1.1.1.0.0
.0.0.0.0.1.0.1.1
.1.1.0.0.0.1.1.0
.0.1.1.0.0.0.1.1
.1.1.0.1.0.0.0.0
.0.0.1.1.1.0.0.0
.0.0.1.0.1.0.0.0

Crossrefs

Sequence in context: A308600 A308604 A018315 * A054964 A057752 A342604

Adjacent sequences: A146217 A146218 A146219 * A146221 A146222 A146223

Keyword

nonn

Author

R. H. Hardin

Status

approved