A146449 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1100-0110-0011 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 3, 7, 13, 37, 103, 247, 705, 2637, 10751, 47763, 249479, 1432497, 8448903, 55396711, 408864319, 3345198367, 30485497915, 317358146063, 3656304314307, 46486480051999, 650411725511243

Offset

1,8

Links

Table of n, a(n) for n=1..28.

Example

Maximal 8 X 8 example
.0.0.0.0.0.1.1.0
.0.0.0.0.1.1.0.1
.0.0.0.1.1.0.1.1
.0.0.1.0.0.1.1.0
.0.1.1.0.0.1.0.0
.1.1.0.1.1.0.0.0
.1.0.1.1.0.0.0.0
.0.1.1.0.0.0.0.0

Crossrefs

Sequence in context: A186721 A177945 A147448 * A145956 A155225 A051842

Adjacent sequences: A146446 A146447 A146448 * A146450 A146451 A146452

Keyword

nonn

Author

R. H. Hardin

Status

approved