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A146221
Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 101-111-010 pattern in any orientation.
0
1, 1, 1, 1, 1, 1, 2, 1, 4, 1, 8, 3, 27, 9, 104, 20, 436, 63, 2340, 272, 15459, 1557, 131790, 10412, 1346197, 77761, 16419748, 729051, 247609178, 8641753
OFFSET
1,7
EXAMPLE
Maximal 9 X 9 example
.0.0.0.0.0.0.0.0.0
.0.0.0.1.0.1.0.0.0
.0.0.0.1.1.1.0.0.0
.0.1.1.0.1.0.1.1.0
.0.0.1.1.0.1.1.0.0
.0.1.1.0.1.0.1.1.0
.0.0.0.1.1.1.0.0.0
.0.0.0.1.0.1.0.0.0
.0.0.0.0.0.0.0.0.0
CROSSREFS
Sequence in context: A147441 A146269 A146679 * A147457 A355226 A107061
KEYWORD
nonn
AUTHOR
STATUS
approved