A146572 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 0100-0100-1111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 17, 17, 57, 57, 369, 369, 6075, 6075, 152201, 152201, 4520107, 4520107, 199476793, 199476793, 15394540581

Offset

1,9

Links

Table of n, a(n) for n=1..23.

Example

Maximal 9 X 9 example
.0.0.0.1.0.1.0.0.0
.0.0.0.1.0.1.0.0.0
.0.1.1.1.0.1.1.1.0
.0.0.0.1.0.1.0.0.0
.0.0.0.0.0.0.0.0.0
.0.0.0.1.0.1.0.0.0
.0.1.1.1.0.1.1.1.0
.0.0.0.1.0.1.0.0.0
.0.0.0.1.0.1.0.0.0

Crossrefs

Sequence in context: A146692 A146439 A146785 * A147211 A147241 A146580

Adjacent sequences: A146569 A146570 A146571 * A146573 A146574 A146575

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved