A146191 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 101-111-100 pattern in any orientation.

1, 1, 1, 1, 3, 13, 31, 85, 561, 4911, 35269, 314409, 4382215, 80159625, 1612619787, 40395227173, 1368159254461, 58890622637327, 3064461664498081, 200721016168368683, 16988612946006051893, 1814141923819418631539

Offset

1,5

Links

Table of n, a(n) for n=1..22.

Example

Maximal 8 X 8 example
.0.0.1.0.1.0.0.0
.0.0.1.1.1.0.0.0
.1.1.0.0.1.0.0.0
.0.1.0.0.0.1.0.1
.1.1.1.0.0.1.1.1
.0.0.0.1.1.0.0.1
.0.0.0.0.1.0.0.0
.0.0.0.1.1.1.0.0

Crossrefs

Sequence in context: A146174 A147134 A146842 * A058264 A242905 A213970

Adjacent sequences: A146188 A146189 A146190 * A146192 A146193 A146194

Keyword

nonn

Author

R. H. Hardin, Oct 27 2008

Status

approved