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A146154
Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only either as two by three or three by two blocks.
0
1, 1, 1, 1, 3, 1, 10, 10, 43, 65, 310, 319, 2668, 3017, 34910, 54223, 689528, 1137739, 18655423, 31210424, 700220638, 1365782613, 38696080322, 86209219516, 3066770236798, 7328473794260, 340900040830525, 897917903090606
OFFSET
1,5
EXAMPLE
Maximal 8 X 8 example
.1.1.0.1.1.0.1.1
.1.1.0.1.1.0.1.1
.1.1.0.1.1.0.1.1
.0.0.0.0.0.0.0.0
.0.0.0.0.0.0.0.0
.1.1.0.1.1.0.1.1
.1.1.0.1.1.0.1.1
.1.1.0.1.1.0.1.1
CROSSREFS
Sequence in context: A185419 A252501 A281000 * A068438 A064060 A176740
KEYWORD
nonn
AUTHOR
R. H. Hardin, Oct 27 2008
STATUS
approved