A146849 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 1100-1111-0001 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 17, 17, 53, 53, 349, 349, 3775, 3775, 72823, 72823, 2211763, 2211763, 82363675, 82363675

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
.1.0.0.0.0.0.0.0.1
.1.1.1.1.0.1.1.1.1
.0.0.1.1.0.1.1.0.0
.0.0.0.0.0.0.0.0.0
.0.0.1.1.0.1.1.0.0
.1.1.1.1.0.1.1.1.1
.1.0.0.0.0.0.0.0.1
.0.0.0.0.0.0.0.0.0

Crossrefs

Sequence in context: A147180 A146644 A146612 * A146716 A146399 A146407

Adjacent sequences: A146846 A146847 A146848 * A146850 A146851 A146852

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved