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A147466
Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1100-1111-0011 pattern in any orientation.
0
1, 1, 1, 1, 1, 9, 21, 63, 297, 1127, 5413, 31109, 218667, 1954511, 18966855, 237663851, 3316716099, 56055493989
OFFSET
1,6
EXAMPLE
Maximal 8 X 8 example
.0.1.1.0.0.1.1.0
.0.1.1.0.0.1.1.0
.1.1.0.0.1.1.0.0
.1.1.0.0.1.1.0.0
.0.0.1.1.0.0.1.1
.0.0.1.1.0.0.1.1
.0.1.1.0.0.1.1.0
.0.1.1.0.0.1.1.0
CROSSREFS
Sequence in context: A020290 A020288 A338007 * A262055 A193276 A173084
KEYWORD
nonn
AUTHOR
STATUS
approved