A146262 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 110-111-101 pattern in any orientation.

1, 1, 1, 1, 1, 1, 9, 33, 57, 93, 311, 1101, 3499, 17317, 84175, 569419, 2944127, 17772493, 117896615, 988499111, 8301329001, 91569781875

Offset

1,7

Links

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

Example

Maximal 8 X 8 example
.0.0.0.0.1.0.1.0
.1.1.0.0.1.1.1.0
.0.1.1.0.1.1.0.0
.1.1.1.0.0.0.0.0
.0.0.0.0.0.1.1.1
.0.0.1.1.0.1.1.0
.0.1.1.1.0.0.1.1
.0.1.0.1.0.0.0.0

Crossrefs

Sequence in context: A337234 A075812 A256868 * A161430 A175369 A046895

Adjacent sequences: A146259 A146260 A146261 * A146263 A146264 A146265

Keyword

nonn

Author

R. H. Hardin

Status

approved