A147164 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 1000-1101-0111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 17, 17, 57, 57, 317, 317, 3151, 3151, 61021, 61021, 1767277, 1767277, 57009275, 57009275

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
.0.0.0.1.0.1.0.0.0
.1.0.1.1.0.1.1.0.1
.1.1.1.0.0.0.1.1.1
.0.0.0.0.0.0.0.0.0
.1.1.1.0.0.0.1.1.1
.1.0.1.1.0.1.1.0.1
.0.0.0.1.0.1.0.0.0
.0.0.0.0.0.0.0.0.0

Crossrefs

Sequence in context: A146684 A146652 A147133 * A146692 A146439 A146785

Adjacent sequences: A147161 A147162 A147163 * A147165 A147166 A147167

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved