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A147238
Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1101-0111-0001 pattern in any orientation.
0
1, 1, 1, 1, 5, 21, 51, 289, 1391, 7677, 54075, 500683, 5608015, 82262213, 1433087781
OFFSET
1,5
EXAMPLE
Maximal 8 X 8 example
.0.0.0.1.1.1.0.1
.0.0.0.0.1.0.1.1
.0.0.0.1.1.0.1.0
.0.0.0.1.0.1.1.1
.1.1.1.0.1.0.0.0
.0.1.0.1.1.0.0.0
.1.1.0.1.0.0.0.0
.1.0.1.1.1.0.0.0
CROSSREFS
Sequence in context: A099979 A366723 A039659 * A316435 A339623 A272013
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 04 2008
STATUS
approved