A146684 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 1100-1000-1111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 17, 17, 57, 57, 265, 265, 2569, 2569, 53981, 53981, 1294213, 1294213, 32947589

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
.1.1.0.0.0.0.0.1.1
.1.0.0.0.0.0.0.0.1
.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
.1.0.0.0.0.0.0.0.1
.1.1.0.0.0.0.0.1.1
.0.0.0.0.0.0.0.0.0

Crossrefs

Sequence in context: A146716 A146399 A146407 * A146652 A147133 A147164

Adjacent sequences: A146681 A146682 A146683 * A146685 A146686 A146687

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved