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A146158
Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only either as two by three or three by two blocks.
0
1, 1, 1, 1, 1, 3, 8, 14, 23, 49, 124, 341, 1108, 3645, 13272, 50449, 210792, 970179, 4987095, 27600222, 171681370, 1133281367, 8288847384, 64922838278, 565664086802, 5311135075018, 55657682314667, 624953409635386
OFFSET
1,6
EXAMPLE
Maximal 8 X 8 example
.0.0.0.1.1.0.0.0
.0.0.0.1.1.0.0.0
.0.0.0.1.1.0.0.0
.1.1.1.0.0.1.1.1
.1.1.1.0.0.1.1.1
.0.0.0.1.1.0.0.0
.0.0.0.1.1.0.0.0
.0.0.0.1.1.0.0.0
CROSSREFS
Sequence in context: A014848 A140479 A264689 * A062354 A257644 A135940
KEYWORD
nonn
AUTHOR
R. H. Hardin, Oct 27 2008
STATUS
approved