A146258 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 110-111-101 pattern in any orientation.

1, 1, 1, 1, 1, 1, 9, 9, 33, 33, 81, 81, 609, 609, 23953, 23953, 643873, 643873, 12050113, 12050113, 545308145, 545308145

Offset

1,7

Links

Table of n, a(n) for n=1..22.

Example

Maximal 8 X 8 example
.1.1.0.0.0.0.1.1
.0.1.1.0.0.1.1.0
.1.1.1.0.0.1.1.1
.0.0.0.0.0.0.0.0
.0.0.0.0.0.0.0.0
.1.1.1.0.0.1.1.1
.0.1.1.0.0.1.1.0
.1.1.0.0.0.0.1.1

Crossrefs

Sequence in context: A147172 A146825 A147029 * A146173 A146190 A147125

Adjacent sequences: A146255 A146256 A146257 * A146259 A146260 A146261

Keyword

nonn

Author

R. H. Hardin

Status

approved