A146254 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 110-111-011 pattern in any orientation.

1, 1, 1, 1, 1, 1, 3, 11, 15, 27, 47, 153, 311, 1151, 2849, 13187, 36901, 183137, 600651, 3599693, 14056563, 100844845, 464890609, 3938830471, 21240835037, 209440142193, 1329357548469, 15466899531131, 115875805461919

Offset

1,7

Links

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

Example

Maximal 8 X 8 example
.0.0.0.0.0.1.1.0
.1.1.0.0.1.1.1.0
.1.1.1.0.1.1.0.0
.0.1.1.0.0.0.0.0
.0.0.0.0.0.1.1.0
.0.0.1.1.0.1.1.1
.0.1.1.1.0.0.1.1
.0.1.1.0.0.0.0.0

Crossrefs

Sequence in context: A323103 A046159 A022410 * A039503 A276971 A366813

Adjacent sequences: A146251 A146252 A146253 * A146255 A146256 A146257

Keyword

nonn

Author

R. H. Hardin

Status

approved