A147253 - OEIS

A147253

Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 11100-00100-00111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 11, 17, 41, 57, 231, 453, 1543, 3457, 18427, 50015, 289401, 862907, 5771143, 20904685, 158696163, 662519097

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

OFFSET

1,9

LINKS

EXAMPLE

Maximal 9 X 9 example

.0.0.0.0.0.1.1.1.0

.1.0.0.0.0.1.0.0.0

.1.0.0.1.1.1.0.0.0

.1.1.1.0.0.0.1.0.0

.0.0.1.0.0.0.1.0.0

.0.0.1.0.0.0.1.1.1

.0.0.0.1.1.1.0.0.1

.0.0.0.1.0.0.0.0.1

.0.1.1.1.0.0.0.0.0

CROSSREFS

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 04 2008

STATUS

approved