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A146721
Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1100-1111-1000 pattern in any orientation.
0
1, 1, 1, 1, 5, 21, 49, 265, 1337, 7025, 55305, 543439, 6271235, 94294061, 1709408045, 38060613237
OFFSET
1,5
EXAMPLE
Maximal 8 X 8 example
.0.1.1.1.0.1.1.1
.0.1.1.0.0.0.1.1
.0.0.1.0.0.0.1.0
.0.0.1.0.0.0.1.0
.0.1.0.0.0.1.0.0
.0.1.0.0.0.1.0.0
.1.1.0.0.0.1.1.0
.1.1.1.0.1.1.1.0
CROSSREFS
Sequence in context: A041825 A022268 A201279 * A099979 A366723 A039659
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 04 2008
STATUS
approved