A147096 Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 1000-1000-1000-1111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 3, 3, 7, 7, 15, 15, 31, 31, 73, 73, 307, 307, 1451, 1451, 6775, 6775, 33773, 33773, 192865

Offset

1,9

Links

Table of n, a(n) for n=1..27.

Example

Maximal 9 X 9 example
.0.0.0.1.0.1.0.0.0
.0.0.0.1.0.1.0.0.0
.0.0.0.1.0.1.0.0.0
.1.1.1.1.0.1.1.1.1
.0.0.0.0.0.0.0.0.0
.1.1.1.1.0.1.1.1.1
.0.0.0.1.0.1.0.0.0
.0.0.0.1.0.1.0.0.0
.0.0.0.1.0.1.0.0.0

Crossrefs

Sequence in context: A357215 A147402 A052551 * A147252 A147104 A147381

Adjacent sequences: A147093 A147094 A147095 * A147097 A147098 A147099

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved