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A146720 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1100-1111-1000 pattern in any orientation. 0
1, 1, 1, 1, 1, 1, 5, 17, 43, 65, 175, 507, 1901, 7015, 35249, 143079, 849399, 4342589, 31597665, 199056275, 1767268871 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,7

LINKS

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

EXAMPLE

Maximal 8 X 8 example

.1.1.1.0.0.0.1.1

.1.1.0.0.1.1.1.1

.0.1.0.0.0.0.0.1

.0.1.0.0.0.0.0.0

.0.0.0.0.0.0.1.0

.1.0.0.0.0.0.1.0

.1.1.1.1.0.0.1.1

.1.1.0.0.0.1.1.1

CROSSREFS

Sequence in context: A055609 A231703 A265193 * A146640 A100705 A100662

Adjacent sequences:  A146717 A146718 A146719 * A146721 A146722 A146723

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 04 2008

STATUS

approved

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Last modified February 20 04:29 EST 2020. Contains 332063 sequences. (Running on oeis4.)