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A146940
Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1111-1111 pattern in any orientation.
0
1, 1, 1, 3, 5, 9, 19, 60, 189, 892, 3177, 18960, 89571, 754227, 4905159, 53337014, 466215312, 6729449504, 78188089715, 1533329125669
OFFSET
1,4
EXAMPLE
Maximal 8 X 8 example
.1.1.0.0.1.1.0.0
.1.1.0.0.1.1.0.0
.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
.0.0.1.1.0.0.1.1
.0.0.1.1.0.0.1.1
CROSSREFS
Sequence in context: A147470 A147010 A146912 * A146251 A281732 A066777
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 04 2008
STATUS
approved