A146593 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 0110-1111-0100 pattern in any orientation.

1, 1, 1, 1, 1, 21, 51, 327, 1675, 7635, 91085, 1248699, 15566521, 331389569, 6715390709, 209774176475, 7949748988669, 377908421650787

Offset

1,6

Links

Table of n, a(n) for n=1..18.

Example

Maximal 8 X 8 example
.0.0.0.0.0.1.1.0
.0.1.0.0.1.1.1.1
.1.1.0.0.0.1.0.0
.1.1.1.0.0.0.1.0
.0.1.0.0.0.1.1.1
.0.0.1.0.0.0.1.1
.1.1.1.1.0.0.1.0
.0.1.1.0.0.0.0.0

Crossrefs

Sequence in context: A242236 A235877 A146838 * A176588 A043133 A039310

Adjacent sequences: A146590 A146591 A146592 * A146594 A146595 A146596

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved