A146718 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1100-1111-1000 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 7, 13, 27, 41, 107, 327, 1681, 5451, 24597, 80545, 454313, 2226033, 18080203, 106915629

Offset

1,9

Links

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

Example

Maximal 9 X 9 example
.0.0.0.0.0.1.0.0.0
.0.0.1.1.1.1.0.0.0
.0.1.0.0.1.1.0.0.0
.0.1.0.0.0.0.1.1.1
.0.1.1.0.0.0.1.1.0
.1.1.1.0.0.0.0.1.0
.0.0.0.1.1.0.0.1.0
.0.0.0.1.1.1.1.0.0
.0.0.0.1.0.0.0.0.0

Crossrefs

Sequence in context: A337433 A067870 A147258 * A146646 A096194 A160889

Adjacent sequences: A146715 A146716 A146717 * A146719 A146720 A146721

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved