A146269 Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 110-111-110 pattern in any orientation.

1, 1, 1, 1, 1, 1, 2, 1, 4, 1, 8, 3, 26, 9, 95, 20, 374, 59, 1990, 238, 12488, 1339, 98678, 8950, 945523, 63227, 10649014, 541368, 148952527

Offset

1,7

Links

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

Example

Maximal 9 X 9 example
.0.0.0.0.1.0.0.0.0
.0.0.0.1.1.1.0.0.0
.0.0.0.1.1.1.0.0.0
.0.1.1.0.0.0.1.1.0
.1.1.1.0.0.0.1.1.1
.0.1.1.0.0.0.1.1.0
.0.0.0.1.1.1.0.0.0
.0.0.0.1.1.1.0.0.0
.0.0.0.0.1.0.0.0.0

Crossrefs

Sequence in context: A115120 A147373 A147441 * A146679 A146221 A147457

Adjacent sequences: A146266 A146267 A146268 * A146270 A146271 A146272

Keyword

nonn

Author

R. H. Hardin

Status

approved