A147456 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 11000-01111-11000 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 6, 11, 18, 27, 52, 137, 404, 1237, 3559, 10401, 31124, 115055, 457260, 2084424, 9632056

Offset

1,10

Links

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

Example

Maximal 10 X 10 example
.0.0.0.0.0.1.1.0.0.0
.0.0.1.1.1.1.0.0.0.0
.0.1.0.0.0.1.1.0.0.0
.0.1.0.0.0.0.0.1.0.1
.0.1.0.0.0.0.0.1.1.1
.1.1.1.0.0.0.0.0.1.0
.1.0.1.0.0.0.0.0.1.0
.0.0.0.1.1.0.0.0.1.0
.0.0.0.0.1.1.1.1.0.0
.0.0.0.1.1.0.0.0.0.0

Crossrefs

Sequence in context: A183199 A172046 A014125 * A230088 A011849 A350104

Adjacent sequences: A147453 A147454 A147455 * A147457 A147458 A147459

Keyword

nonn

Author

R. H. Hardin

Status

approved