A147123 Number of n X n binary arrays with all ones connected only in a 1000-1000-1111-1000 pattern in any orientation.

1, 1, 1, 9, 33, 105, 641, 8787, 211111, 4653287, 141740021, 6813049829, 531641820663

Offset

1,4

Links

Table of n, a(n) for n=1..13.

Example

Maximal 8 X 8 example
.1.0.0.0.1.1.1.1
.1.1.1.1.0.0.1.0
.1.0.0.0.0.0.1.0
.1.0.0.0.0.0.1.0
.0.1.0.0.0.0.0.1
.0.1.0.0.0.0.0.1
.0.1.0.0.1.1.1.1
.1.1.1.1.0.0.0.1

Crossrefs

Sequence in context: A220165 A036543 A147269 * A147107 A147115 A147261

Adjacent sequences: A147120 A147121 A147122 * A147124 A147125 A147126

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved