A146932 - OEIS

A146932

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

1, 1, 1, 1, 1, 5, 9, 21, 65, 198, 664, 2279, 9527, 44776, 245082, 1574117, 10939250, 91288331, 843940046

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,6

LINKS

EXAMPLE

Maximal 8 X 8 example

.1.1.1.0.1.0.0.1

.0.1.0.0.1.1.1.1

.0.1.0.0.1.0.0.1

.1.1.1.0.0.0.0.0

.0.0.0.0.0.1.1.1

.1.0.0.1.0.0.1.0

.1.1.1.1.0.0.1.0

.1.0.0.1.0.1.1.1

CROSSREFS

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 04 2008

STATUS

approved