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A147271
Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1000-1000-1111-0001 pattern in any orientation.
0
1, 1, 1, 1, 1, 3, 9, 23, 45, 169, 1061, 6743, 40273, 284761, 2852385, 36414365, 522818739, 8493813357, 169218922641
OFFSET
1,6
EXAMPLE
Maximal 8 X 8 example
.0.0.0.0.0.0.0.0
.0.0.0.0.0.0.0.0
.0.0.0.0.1.0.0.0
.0.0.0.0.1.1.1.1
.0.0.1.1.0.0.0.1
.0.0.0.1.0.0.0.1
.0.0.0.1.0.0.0.0
.0.0.0.1.1.1.0.0
CROSSREFS
Sequence in context: A029512 A210027 A018555 * A230119 A146693 A227259
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 04 2008
STATUS
approved