A146040 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all 1's connected only in a 2 X 4 tee 1,1 1,2 1,3 2,3 1,4 in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 29, 29, 249, 249, 4021, 4021, 99935, 99935, 4398251, 4398251, 362789159, 362789159, 47338031953, 47338031953, 10727733486159, 10727733486159

Offset

1,9

Links

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

Example

Maximal 9 X 9 example
.1.0.0.1.0.1.0.0.1
.1.1.0.1.0.1.0.1.1
.1.0.1.1.0.1.1.0.1
.1.0.0.1.0.1.0.0.1
.0.0.0.0.0.0.0.0.0
.1.0.0.1.0.1.0.0.1
.1.0.1.1.0.1.1.0.1
.1.1.0.1.0.1.0.1.1
.1.0.0.1.0.1.0.0.1

Crossrefs

Sequence in context: A146226 A146423 A146129 * A146017 A210267 A210309

Adjacent sequences: A146037 A146038 A146039 * A146041 A146042 A146043

Keyword

nonn

Author

R. H. Hardin, Oct 26 2008

Status

approved