A147199 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1100-0100-0111-0001 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 9, 25, 37, 77, 207, 663, 1517, 4967, 16733, 80643, 308521, 1536069, 6622503, 39983439, 198749745, 1357116341

Offset

1,9

Links

Table of n, a(n) for n=1..24.

Example

Maximal 9 X 9 example
.0.0.0.1.0.1.0.0.0
.0.1.1.1.0.1.1.1.0
.0.1.0.0.0.0.0.1.0
.1.1.0.0.0.0.0.1.1
.0.0.0.0.0.0.0.0.0
.1.1.0.0.0.0.0.1.1
.0.1.0.0.0.0.0.1.0
.0.1.1.1.0.1.1.1.0
.0.0.0.1.0.1.0.0.0

Crossrefs

Sequence in context: A372724 A348234 A226647 * A147403 A241764 A044451

Adjacent sequences: A147196 A147197 A147198 * A147200 A147201 A147202

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved