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A147480
Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1100-1111-1100 pattern in any orientation.
0
1, 1, 1, 1, 1, 9, 21, 73, 310, 1107, 5232, 33319, 240772, 2106289, 21011261, 262231181, 3633528079, 62517538899
OFFSET
1,6
EXAMPLE
Maximal 8 X 8 example
.0.0.1.1.0.0.0.0
.1.1.1.1.0.0.0.0
.0.0.1.1.0.0.1.1
.1.1.0.0.1.1.1.1
.1.1.1.1.0.0.1.1
.1.1.0.0.1.1.0.0
.0.0.0.0.1.1.1.1
.0.0.0.0.1.1.0.0
CROSSREFS
Sequence in context: A173084 A137340 A075640 * A146396 A146681 A269633
KEYWORD
nonn
AUTHOR
STATUS
approved