A147041 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 0100-0100-1111-0100 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 3, 15, 27, 43, 77, 211, 651, 2217, 7655, 29663

Offset

1,8

Links

Table of n, a(n) for n=1..17.

Example

Maximal 8 X 8 example
.0.0.1.0.0.0.1.0
.1.1.1.1.0.0.1.0
.0.0.1.0.1.1.1.1
.0.0.1.0.0.0.1.0
.0.1.0.0.0.1.0.0
.1.1.1.1.0.1.0.0
.0.1.0.0.1.1.1.1
.0.1.0.0.0.1.0.0

Crossrefs

Sequence in context: A105549 A080065 A017557 * A347536 A002259 A050848

Adjacent sequences: A147038 A147039 A147040 * A147042 A147043 A147044

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved