A146632 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1010-1111-0010 pattern in any orientation.

1, 1, 1, 1, 1, 1, 5, 15, 45, 69, 191, 523, 2197, 7857, 44519, 172481, 1142709, 5725361, 46827941, 294096301, 2934334465, 22633368087

Offset

1,7

Links

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

Example

Maximal 8 X 8 example
.0.0.0.0.1.0.1.0
.1.1.0.1.1.1.1.0
.0.1.0.0.1.0.0.0
.1.1.1.0.0.0.1.0
.0.1.0.0.0.1.1.1
.0.0.0.1.0.0.1.0
.0.1.1.1.1.0.1.1
.0.1.0.1.0.0.0.0

Crossrefs

Sequence in context: A295179 A274020 A109952 * A076103 A094283 A373300

Adjacent sequences: A146629 A146630 A146631 * A146633 A146634 A146635

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved