A146187 - OEIS

A146187

Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 110-111-100 pattern in any orientation.

1, 1, 1, 1, 9, 39, 227, 1199, 6097, 63869, 840409, 12862601, 284127507, 7552975051, 252656207179, 10547338792841

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

OFFSET

1,5

LINKS

EXAMPLE

Maximal 8 X 8 example

.0.0.1.1.0.1.1.0

.0.1.1.1.0.1.1.1

.1.0.0.1.0.1.0.0

.1.1.1.0.0.0.1.1

.1.1.0.0.0.1.1.1

.0.0.1.0.1.0.0.1

.1.1.1.0.1.1.1.0

.0.1.1.0.1.1.0.0

CROSSREFS

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 27 2008

STATUS

approved