A146875 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1110-0100-0111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 5, 13, 25, 41, 109, 333, 897, 2841, 13365, 66133, 320121, 1501457, 8213389, 51555309

Offset

1,9

Links

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

Example

Maximal 9 X 9 example
.0.0.0.0.1.1.1.0.0
.0.0.0.0.0.1.0.0.0
.0.0.0.1.1.1.0.0.1
.0.0.1.0.0.0.1.1.1
.1.0.1.0.0.0.1.0.1
.1.1.1.0.0.0.1.0.0
.1.0.0.1.1.1.0.0.0
.0.0.0.1.0.0.0.0.0
.0.0.1.1.1.0.0.0.0

Crossrefs

Sequence in context: A146590 A098483 A147205 * A241233 A064276 A240001

Adjacent sequences: A146872 A146873 A146874 * A146876 A146877 A146878

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved