A146916 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 0100-1110-0111-0010 pattern in any orientation.

1, 1, 1, 3, 1, 5, 9, 25, 65, 311, 777, 5163, 19629, 179101, 938309, 11522939, 83049733, 1385281995, 13583413581, 310426685067, 4145583315227, 129859229238145

Offset

1,4

Links

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

Example

Maximal 8 X 8 example
.0.0.1.0.0.0.1.0
.0.1.1.1.0.1.1.1
.1.1.1.0.1.1.1.0
.0.1.0.0.0.1.0.0
.0.0.1.0.0.0.1.0
.0.1.1.1.0.1.1.1
.1.1.1.0.1.1.1.0
.0.1.0.0.0.1.0.0

Crossrefs

Sequence in context: A225855 A201751 A202504 * A146255 A331432 A122366

Adjacent sequences: A146913 A146914 A146915 * A146917 A146918 A146919

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved