A146838 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1001-1111-0100 pattern in any orientation.

1, 1, 1, 1, 1, 21, 51, 217, 1233, 6449, 45131, 442147, 4714111, 71906123, 1148024329, 26742683865, 642806579973

Offset

1,6

Links

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

Example

Maximal 8 X 8 example
.0.0.0.0.0.1.1.0
.0.1.0.0.0.0.1.0
.1.1.1.1.0.0.1.1
.1.0.0.1.0.1.1.0
.0.1.1.0.1.0.0.1
.1.1.0.0.1.1.1.1
.0.1.0.0.0.0.1.0
.0.1.1.0.0.0.0.0

Crossrefs

Sequence in context: A305002 A242236 A235877 * A146593 A176588 A043133

Adjacent sequences: A146835 A146836 A146837 * A146839 A146840 A146841

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved