A146818 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1000-1110-0111 pattern in any orientation.

1, 1, 1, 1, 3, 9, 23, 59, 317, 2143, 14651, 111875, 1267355, 18704275, 315484781, 6350976523, 167797579971, 5630142919363, 228828878480313

Offset

1,5

Links

Table of n, a(n) for n=1..19.

Example

Maximal 8 X 8 example
.0.0.1.1.0.0.0.0
.0.0.0.1.1.0.0.1
.1.0.0.1.1.0.1.1
.1.1.1.0.1.0.1.1
.0.1.1.1.0.1.1.0
.0.0.0.0.1.0.0.0
.0.0.1.1.1.0.0.0
.0.1.1.1.0.0.0.0

Crossrefs

Sequence in context: A191342 A077847 A027058 * A309301 A323798 A180488

Adjacent sequences: A146815 A146816 A146817 * A146819 A146820 A146821

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved