A146781 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 0010-1010-1111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 5, 17, 37, 69, 119, 413, 1361, 4953, 21841, 100255, 486625, 2729263, 14571959, 98507721, 677047259

Offset

1,7

Links

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

Example

Maximal 8 X 8 example
.0.0.0.0.0.1.1.0
.1.1.1.1.0.0.1.0
.1.0.1.0.1.1.1.0
.0.0.1.0.0.0.1.0
.0.1.0.0.0.1.0.0
.0.1.1.1.0.1.0.1
.0.1.0.0.1.1.1.1
.0.1.1.0.0.0.0.0

Crossrefs

Sequence in context: A273250 A053755 A162373 * A338277 A348228 A107199

Adjacent sequences: A146778 A146779 A146780 * A146782 A146783 A146784

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved