A147057 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 0100-1101-0111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 3, 15, 43, 67, 135, 405, 1643, 5861, 31427, 120095, 674029, 3441725, 24151139, 153308175, 1325530085

Offset

1,7

Links

Table of n, a(n) for n=1..21.

Example

Maximal 8 X 8 example
.0.0.1.0.0.1.1.0
.1.0.1.1.0.1.0.0
.1.1.1.0.0.1.1.1
.0.0.0.0.0.0.1.0
.0.1.0.0.0.0.0.0
.1.1.1.0.0.1.1.1
.0.0.1.0.1.1.0.1
.0.1.1.0.0.1.0.0

Crossrefs

Sequence in context: A192060 A316642 A146805 * A330322 A101165 A127407

Adjacent sequences: A147054 A147055 A147056 * A147058 A147059 A147060

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved