A147234 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1101-0111-0001 pattern in any orientation.

1, 1, 1, 1, 3, 7, 19, 49, 195, 1111, 7177, 51609, 452845, 5123643, 72369101, 1214915609, 24818665423, 626087799933, 19508645488885, 741333829643879

Offset

1,5

Links

Table of n, a(n) for n=1..20.

Example

Maximal 8 X 8 example
.0.0.1.1.1.0.0.0
.0.0.0.1.0.0.0.1
.1.0.0.1.1.0.1.1
.1.1.1.0.1.0.1.0
.1.0.1.1.0.1.1.1
.0.0.0.0.1.0.0.0
.0.0.1.1.1.0.0.0
.0.1.1.0.1.0.0.0

Crossrefs

Sequence in context: A116903 A298416 A151266 * A171854 A182895 A087224

Adjacent sequences: A147231 A147232 A147233 * A147235 A147236 A147237

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved