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A146843
Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all 1's connected only in a 1001-1111-1000 pattern in any orientation.
0
1, 1, 1, 1, 1, 1, 1, 1, 3, 9, 19, 33, 61, 167, 557, 1931, 7517, 29489, 124159, 584129, 3130749, 18534977
OFFSET
1,9
EXAMPLE
Maximal 9 X 9 example
.0.0.0.1.0.0.1.0.0
.0.0.0.1.1.1.1.0.0
.0.0.0.1.0.0.0.1.1
.1.1.1.0.0.0.0.1.0
.0.1.0.0.0.0.0.1.0
.0.1.0.0.0.0.1.1.1
.1.1.0.0.0.1.0.0.0
.0.0.1.1.1.1.0.0.0
.0.0.1.0.0.1.0.0.0
CROSSREFS
Sequence in context: A147055 A146638 A147135 * A146630 A146710 A146803
KEYWORD
nonn,more
AUTHOR
R. H. Hardin, Nov 04 2008
STATUS
approved