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A146058
Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 2X3 U in any orientation.
0
1, 1, 1, 1, 1, 1, 3, 7, 13, 21, 51, 159, 577, 2001, 7625, 31703, 159573, 881761, 5519227, 36692597, 286423433, 2406566921, 23662937019, 247567053249, 2997634212141, 39099498214505, 595262340859501, 9726061577357237, 184962190180592957
OFFSET
1,7
EXAMPLE
Maximal 8 X 8 example
.0.0.0.1.1.0.0.0
.0.0.0.0.1.0.0.0
.0.0.0.1.1.0.0.0
.1.0.1.0.0.1.1.1
.1.1.1.0.0.1.0.1
.0.0.0.1.1.0.0.0
.0.0.0.1.0.0.0.0
.0.0.0.1.1.0.0.0
CROSSREFS
Sequence in context: A147501 A147335 A147464 * A155354 A136219 A078582
KEYWORD
nonn
AUTHOR
R. H. Hardin, Oct 26 2008
STATUS
approved