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A146623
Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 1001-1111 pattern in any orientation.
0
1, 1, 1, 1, 1, 1, 1, 3, 1, 5, 1, 7, 5, 21, 13, 69, 33, 309, 131, 1529, 465, 8153, 2505, 52849, 18109, 418127, 137539, 4312045, 1253575, 52848473
OFFSET
1,8
EXAMPLE
Maximal 8 X 8 example
.0.0.1.0.0.1.0.0
.0.0.1.1.1.1.0.0
.1.1.0.0.0.0.1.1
.0.1.0.0.0.0.1.0
.0.1.0.0.0.0.1.0
.1.1.0.0.0.0.1.1
.0.0.1.1.1.1.0.0
.0.0.1.0.0.1.0.0
CROSSREFS
Sequence in context: A254938 A244149 A147410 * A197943 A318828 A318827
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 04 2008
STATUS
approved