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A146827
Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1000-1111-0100-0100 pattern in any orientation.
0
1, 1, 1, 1, 1, 1, 1, 1, 5, 9, 21, 33, 75, 191, 769, 2241, 10975, 33339, 159399, 627233, 4142099, 21519301
OFFSET
1,9
EXAMPLE
Maximal 9 X 9 example
.0.0.0.0.1.1.0.0.0
.0.0.1.1.1.0.0.0.0
.0.1.0.0.1.0.0.0.0
.0.1.0.0.1.0.0.0.1
.1.1.1.1.0.1.1.1.1
.1.0.0.0.1.0.0.1.0
.0.0.0.0.1.0.0.1.0
.0.0.0.0.1.1.1.0.0
.0.0.0.1.1.0.0.0.0
CROSSREFS
Sequence in context: A273486 A146867 A068481 * A297360 A216414 A147018
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 04 2008
STATUS
approved