A146878 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1110-0100-0111 pattern in any orientation.

1, 1, 1, 1, 1, 9, 41, 249, 1137, 4177, 27849, 254297, 2360945, 31718257, 561884345, 12949529033, 316511614977

Offset

1,6

Links

Table of n, a(n) for n=1..17.

Example

Maximal 8 X 8 example
.0.0.0.0.0.1.0.0
.1.1.1.0.0.1.1.1
.0.1.0.0.0.1.0.1
.0.1.1.1.0.0.0.1
.1.0.0.0.1.1.1.0
.1.0.1.0.0.0.1.0
.1.1.1.0.0.1.1.1
.0.0.1.0.0.0.0.0

Crossrefs

Sequence in context: A171422 A129793 A304361 * A177259 A247884 A301803

Adjacent sequences: A146875 A146876 A146877 * A146879 A146880 A146881

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved