A146426 Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 1010-1111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 3, 13, 13, 35, 35, 165, 165, 727, 727, 4597, 4597, 49361, 49361

Offset

1,11

Links

Table of n, a(n) for n=1..24.

Example

Maximal 11 X 11 example
.0.0.0.1.1.0.1.1.0.0.0
.0.0.0.0.1.0.1.0.0.0.0
.0.0.0.1.1.0.1.1.0.0.0
.1.0.1.0.1.0.1.0.1.0.1
.1.1.1.1.0.0.0.1.1.1.1
.0.0.0.0.0.0.0.0.0.0.0
.1.1.1.1.0.0.0.1.1.1.1
.1.0.1.0.1.0.1.0.1.0.1
.0.0.0.1.1.0.1.1.0.0.0
.0.0.0.0.1.0.1.0.0.0.0
.0.0.0.1.1.0.1.1.0.0.0

Crossrefs

Sequence in context: A146844 A146193 A146727 * A146051 A146229 A146020

Adjacent sequences: A146423 A146424 A146425 * A146427 A146428 A146429

Keyword

nonn

Author

R. H. Hardin

Status

approved