A146931 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1001-1111-1001 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 3, 7, 14, 22, 37, 79, 162, 380, 937, 2496, 7209, 22236, 73304, 252500, 902438, 3477063, 13836097, 60384897, 273397251, 1352635265, 7039542506, 39611966803

Offset

1,8

Links

Table of n, a(n) for n=1..29.

Example

Maximal 8 X 8 example
.1.0.0.1.0.1.1.1
.1.1.1.1.0.0.1.0
.1.0.0.1.0.0.1.0
.0.0.0.0.0.1.1.1
.1.1.1.0.0.0.0.0
.0.1.0.0.1.0.0.1
.0.1.0.0.1.1.1.1
.1.1.1.0.1.0.0.1

Crossrefs

Sequence in context: A156859 A173209 A331240 * A176675 A213077 A294400

Adjacent sequences: A146928 A146929 A146930 * A146932 A146933 A146934

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved