A146817 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 1000-1110-0111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 17, 17, 65, 65, 429, 429, 5631, 5631, 146823, 146823, 4351701, 4351701, 186793381, 186793381

Offset

1,9

Links

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

Example

Maximal 9 X 9 example
.0.0.0.0.0.0.0.0.0
.1.0.0.0.0.0.0.0.1
.1.1.1.0.0.0.1.1.1
.0.1.1.1.0.1.1.1.0
.0.0.0.0.0.0.0.0.0
.0.1.1.1.0.1.1.1.0
.1.1.1.0.0.0.1.1.1
.1.0.0.0.0.0.0.0.1
.0.0.0.0.0.0.0.0.0

Crossrefs

Sequence in context: A146048 A146809 A147233 * A146660 A070852 A146596

Adjacent sequences: A146814 A146815 A146816 * A146818 A146819 A146820

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved