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A145764
Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only either three adjacent vertically or three adjacent horizontally.
0
1, 1, 5, 5, 24, 73, 566, 2483, 32841, 234437, 5307036, 61459976, 2279718182, 44700555075, 2739362168120, 88170556642974, 8988213154883058
OFFSET
1,3
CROSSREFS
Sequence in context: A090936 A366443 A262117 * A165826 A256693 A255458
KEYWORD
nonn
AUTHOR
R. H. Hardin, Oct 17 2008
STATUS
approved