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A146223 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 101-111-010 pattern in any orientation. 0
1, 1, 1, 1, 5, 21, 64, 303, 1134, 7339, 57196, 589857, 6245651, 99774377, 1593180484, 36586038636, 878744243108, 30250721237881 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

LINKS

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

EXAMPLE

Maximal 8 X 8 example

.0.0.0.0.0.1.0.1

.0.0.0.0.0.1.1.1

.0.1.0.0.0.0.1.0

.1.1.1.0.0.1.0.1

.1.0.1.0.0.1.1.1

.0.1.0.0.0.0.1.0

.1.1.1.0.0.0.0.0

.1.0.1.0.0.0.0.0

CROSSREFS

Sequence in context: A196631 A342379 A146822 * A181093 A055384 A271540

Adjacent sequences:  A146220 A146221 A146222 * A146224 A146225 A146226

KEYWORD

nonn

AUTHOR

R. H. Hardin

STATUS

approved

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Last modified November 30 17:12 EST 2021. Contains 349424 sequences. (Running on oeis4.)