A146238 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 110-111-001 pattern in any orientation.

1, 1, 1, 1, 1, 1, 13, 41, 61, 189, 645, 2565, 9811, 68255, 363653, 2795931, 15874613, 158718393, 1217432647, 15841966869, 160951013553, 2781799777913, 35696899329059

Offset

1,7

Links

Table of n, a(n) for n=1..23.

Example

Maximal 8 X 8 example
.0.0.0.0.1.1.0.0
.0.0.0.0.1.1.0.0
.1.1.0.1.1.0.0.0
.1.1.1.0.0.1.0.0
.0.0.1.0.0.1.1.1
.0.0.0.1.1.0.1.1
.0.0.1.1.0.0.0.0
.0.0.1.1.0.0.0.0

Crossrefs

Sequence in context: A122730 A101167 A334557 * A039339 A031373 A043162

Adjacent sequences: A146235 A146236 A146237 * A146239 A146240 A146241

Keyword

nonn

Author

R. H. Hardin

Status

approved