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A146062
Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 2X3 U in any orientation.
0
1, 1, 1, 5, 13, 37, 193, 825, 4833, 42541, 409765, 5652913, 85462407, 1745289105, 41548085965, 1274611587285, 46878706682435, 2328792987017875
OFFSET
1,4
EXAMPLE
Maximal 8 X 8 example
.1.1.1.0.0.1.1.1
.1.0.1.0.0.1.0.1
.0.0.0.0.0.0.0.0
.1.0.1.0.0.1.1.1
.1.1.1.0.0.1.0.1
.0.0.0.0.0.0.0.0
.1.0.1.0.0.1.0.1
.1.1.1.0.0.1.1.1
CROSSREFS
Sequence in context: A125734 A146925 A146452 * A201612 A129924 A360797
KEYWORD
nonn
AUTHOR
R. H. Hardin, Oct 26 2008
STATUS
approved