A146923 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 0110-1111-0110 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 6, 12, 19, 29, 56, 159, 456, 1350, 3940, 11848, 42451, 167584, 713562, 3187201

Offset

1,8

Links

Table of n, a(n) for n=1..21.

Example

Maximal 8 X 8 example
.0.0.0.1.1.0.0.0
.0.0.1.1.1.1.0.0
.0.1.0.1.1.0.1.0
.1.1.1.0.0.1.1.1
.1.1.1.0.0.1.1.1
.0.1.0.1.1.0.1.0
.0.0.1.1.1.1.0.0
.0.0.0.1.1.0.0.0

Crossrefs

Sequence in context: A051936 A365702 A215342 * A349791 A256977 A087883

Adjacent sequences: A146920 A146921 A146922 * A146924 A146925 A146926

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved