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A146036
Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 3X3 el 1,1 1,2 1,3 2,3 3,3 in any orientation.
0
1, 1, 1, 1, 1, 1, 11, 17, 43, 77, 281, 645, 3017, 9213, 61533, 218977, 1561879, 6900617, 60762405, 333893691, 3718652761, 25349082469, 352708796463, 2947039725027
OFFSET
1,7
EXAMPLE
Maximal 8 X 8 example
.0.1.0.0.0.0.0.0
.0.1.0.0.0.1.1.1
.0.1.1.1.0.1.0.0
.0.0.0.0.0.1.0.0
.0.0.1.0.0.0.0.0
.0.0.1.0.1.1.1.0
.1.1.1.0.0.0.1.0
.0.0.0.0.0.0.1.0
CROSSREFS
Sequence in context: A187060 A190800 A191456 * A248482 A267772 A046122
KEYWORD
nonn
AUTHOR
R. H. Hardin, Oct 26 2008
STATUS
approved