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A146143
Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 5-point barb 1,1 1,2 2,2 2,3 3,2 in any orientation.
0
1, 1, 1, 1, 13, 51, 327, 1743, 13905, 216443, 3286293, 80038799, 2242888197, 93345565591, 4572631279405, 334861611729305
OFFSET
1,5
EXAMPLE
Maximal 8 X 8 example
.0.1.1.0.0.0.1.0
.1.1.0.0.0.1.1.1
.0.1.0.0.1.0.0.1
.0.0.1.0.1.1.1.0
.0.1.1.1.0.1.0.0
.1.0.0.1.0.0.1.0
.1.1.1.0.0.0.1.1
.0.1.0.0.0.1.1.0
CROSSREFS
Sequence in context: A332589 A022283 A135971 * A108919 A002792 A183941
KEYWORD
nonn
AUTHOR
R. H. Hardin, Oct 27 2008
STATUS
approved