A147104 Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 1000-1000-1100-0111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 3, 3, 7, 7, 15, 15, 33, 33, 93, 93, 429, 429, 2069, 2069, 10289, 10289, 55429, 55429, 387995, 387995

Offset

1,9

Links

Table of n, a(n) for n=1..28.

Example

Maximal 9 X 9 example
.0.0.0.1.0.1.0.0.0
.0.0.0.1.0.1.0.0.0
.0.0.1.1.0.1.1.0.0
.1.1.1.0.0.0.1.1.1
.0.0.0.0.0.0.0.0.0
.1.1.1.0.0.0.1.1.1
.0.0.1.1.0.1.1.0.0
.0.0.0.1.0.1.0.0.0
.0.0.0.1.0.1.0.0.0

Crossrefs

Sequence in context: A052551 A147096 A147252 * A147381 A146035 A147190

Adjacent sequences: A147101 A147102 A147103 * A147105 A147106 A147107

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved