A146624 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1001-1111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 7, 15, 27, 59, 155, 405, 1359, 4729, 17093, 68787, 322325, 1555247, 8826433, 52320689, 346500913, 2442891583, 19699289407, 167408986709, 1625563585505

Offset

1,7

Links

Table of n, a(n) for n=1..25.

Example

Maximal 8 X 8 example
.0.0.0.0.0.1.1.0
.1.0.0.1.0.1.0.0
.1.1.1.1.0.1.0.0
.0.0.0.0.0.1.1.0
.0.1.1.0.0.0.0.0
.0.0.1.0.1.1.1.1
.0.0.1.0.1.0.0.1
.0.1.1.0.0.0.0.0

Crossrefs

Sequence in context: A226470 A063611 A292379 * A239934 A193553 A274090

Adjacent sequences: A146621 A146622 A146623 * A146625 A146626 A146627

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved