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A147026 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 01000-11111-01000 pattern in any orientation. 0
1, 1, 1, 1, 1, 9, 17, 35, 145, 589, 2723, 16121, 110705, 888953, 8435682, 98480917, 1294018001, 21003172843 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,6

LINKS

Table of n, a(n) for n=1..18.

EXAMPLE

Maximal 8 X 8 example

.0.1.0.0.1.0.0.0

.0.1.0.1.1.1.1.1

.0.1.0.0.1.0.0.0

.1.1.1.0.0.0.1.0

.0.1.0.0.0.1.1.1

.0.0.0.1.0.0.1.0

.1.1.1.1.1.0.1.0

.0.0.0.1.0.0.1.0

CROSSREFS

Sequence in context: A147279 A173788 A097478 * A055393 A147082 A145941

Adjacent sequences:  A147023 A147024 A147025 * A147027 A147028 A147029

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 04 2008

STATUS

approved

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Last modified November 27 12:51 EST 2021. Contains 349394 sequences. (Running on oeis4.)