A147238 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1101-0111-0001 pattern in any orientation.

1, 1, 1, 1, 5, 21, 51, 289, 1391, 7677, 54075, 500683, 5608015, 82262213, 1433087781

Offset

1,5

Links

Table of n, a(n) for n=1..15.

Example

Maximal 8 X 8 example
.0.0.0.1.1.1.0.1
.0.0.0.0.1.0.1.1
.0.0.0.1.1.0.1.0
.0.0.0.1.0.1.1.1
.1.1.1.0.1.0.0.0
.0.1.0.1.1.0.0.0
.1.1.0.1.0.0.0.0
.1.0.1.1.1.0.0.0

Crossrefs

Sequence in context: A099979 A366723 A039659 * A316435 A339623 A272013

Adjacent sequences: A147235 A147236 A147237 * A147239 A147240 A147241

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved