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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,6

LINKS

Table of n, a(n) for n=1..21.

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: A009951 A274974 A251142 * A147346 A147452 A146782

Adjacent sequences:  A146284 A146285 A146286 * A146288 A146289 A146290

KEYWORD

nonn

AUTHOR

R. H. Hardin

STATUS

approved

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Last modified August 18 18:04 EDT 2017. Contains 290732 sequences.