A146580 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 0100-1100-0111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 17, 17, 57, 57, 457, 457, 7575, 7575, 206575, 206575, 7284891, 7284891, 429058537, 429058537, 43146239725, 43146239725

Offset

1,9

Links

Table of n, a(n) for n=1..24.

Example

Maximal 9 X 9 example
.1.1.1.0.0.0.1.1.1
.0.0.1.1.0.1.1.0.0
.0.0.1.0.0.0.1.0.0
.0.0.0.0.0.0.0.0.0
.0.0.0.0.0.0.0.0.0
.0.0.0.0.0.0.0.0.0
.0.0.1.0.0.0.1.0.0
.0.0.1.1.0.1.1.0.0
.1.1.1.0.0.0.1.1.1

Crossrefs

Sequence in context: A146572 A147211 A147241 * A146455 A146048 A146809

Adjacent sequences: A146577 A146578 A146579 * A146581 A146582 A146583

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved