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A146042
Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 2X4 tee 1,1 1,2 1,3 2,3 1,4 in any orientation.
0
1, 1, 1, 1, 1, 3, 5, 11, 21, 41, 165, 701, 2953, 12345, 51325, 344201, 2572877, 21631323, 180106811, 1718811817, 19639803327, 281005626019, 4302161174593, 75232261306781, 1397819874484453, 32083258430460691
OFFSET
1,6
EXAMPLE
Maximal 8 X 8 example
.0.0.0.0.0.0.0.0
.0.0.1.1.1.1.0.0
.0.1.0.0.1.0.1.0
.0.1.0.0.0.1.1.0
.0.1.1.0.0.0.1.0
.0.1.0.1.0.0.1.0
.0.0.1.1.1.1.0.0
.0.0.0.0.0.0.0.0
CROSSREFS
Sequence in context: A372451 A192664 A122997 * A291219 A284358 A283584
KEYWORD
nonn
AUTHOR
R. H. Hardin, Oct 26 2008
STATUS
approved