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A146267
Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 110-111-110 pattern in any orientation.
0
1, 1, 1, 1, 3, 9, 20, 59, 238, 1339, 8950, 63227, 541368, 5931901, 82015459, 1400527040, 28248253548, 677346206953, 19987158806408, 732068950428064, 33003291678037712, 1801673455589720405, 118568477345258796542
OFFSET
1,5
EXAMPLE
Maximal 8 X 8 example
.0.0.0.1.1.0.0.0
.0.0.1.1.1.0.0.0
.0.1.0.1.1.0.0.0
.1.1.1.0.0.0.1.1
.1.1.1.0.0.1.1.1
.0.0.0.0.1.0.1.1
.0.0.0.1.1.1.0.0
.0.0.0.1.1.1.0.0
CROSSREFS
Sequence in context: A147416 A078841 A147387 * A151420 A196294 A196212
KEYWORD
nonn
AUTHOR
STATUS
approved