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A146287
Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 111-110-111 pattern in any orientation.
0
1, 1, 1, 1, 1, 13, 49, 205, 661, 1997, 13307, 88591, 614455, 6581035, 95397503, 1522572859, 23440615715, 367710019427, 8011532526037, 207007785752989, 6626542824985383
OFFSET
1,6
EXAMPLE
Maximal 8 X 8 example
.0.0.0.0.0.1.1.1
.1.1.1.0.0.0.1.1
.1.1.0.0.0.1.1.1
.1.1.1.0.0.0.0.0
.0.0.0.0.0.1.1.1
.1.1.1.0.0.0.1.1
.1.1.0.0.0.1.1.1
.1.1.1.0.0.0.0.0
CROSSREFS
Sequence in context: A274974 A251142 A319086 * A289999 A147346 A147452
KEYWORD
nonn
AUTHOR
STATUS
approved