A146841 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 1001-1111-1000 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 17, 17, 53, 53, 329, 329, 2805, 2805, 46829, 46829, 1364733, 1364733, 44089225, 44089225

Offset

1,9

Links

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

Example

Maximal 9 X 9 example
.0.0.0.0.0.0.0.0.0
.0.0.0.1.0.1.0.0.0
.1.1.1.1.0.1.1.1.1
.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
.1.1.1.1.0.1.1.1.1
.0.0.0.1.0.1.0.0.0
.0.0.0.0.0.0.0.0.0

Crossrefs

Sequence in context: A146700 A146708 A146463 * A147180 A146644 A146612

Adjacent sequences: A146838 A146839 A146840 * A146842 A146843 A146844

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved