A147133 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 1000-1001-1111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 17, 17, 57, 57, 277, 277, 2295, 2295, 39117, 39117, 1059135, 1059135, 28274373

Offset

1,9

Links

Table of n, a(n) for n=1..21.

Example

Maximal 9 X 9 example
.0.0.0.0.0.0.0.0.0
.0.0.0.1.0.1.0.0.0
.1.0.0.1.0.1.0.0.1
.1.1.1.1.0.1.1.1.1
.0.0.0.0.0.0.0.0.0
.1.1.1.1.0.1.1.1.1
.1.0.0.1.0.1.0.0.1
.0.0.0.1.0.1.0.0.0
.0.0.0.0.0.0.0.0.0

Crossrefs

Sequence in context: A146407 A146684 A146652 * A147164 A146692 A146439

Adjacent sequences: A147130 A147131 A147132 * A147134 A147135 A147136

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved