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A146418 Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 1000-1111-1000 pattern in any orientation. 0
1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 4, 1, 9, 3, 31, 9, 107, 21, 365, 62, 1813, 243, 11236, 1174, 84454, 7129, 738542, 48787, 7473236, 396149 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,9

LINKS

Table of n, a(n) for n=1..30.

EXAMPLE

Maximal 9 X 9 example

.0.0.0.1.1.1.0.0.0

.0.0.0.0.1.0.0.0.0

.0.0.0.0.1.0.0.0.0

.1.0.0.0.1.0.0.0.1

.1.1.1.1.0.1.1.1.1

.1.0.0.0.1.0.0.0.1

.0.0.0.0.1.0.0.0.0

.0.0.0.0.1.0.0.0.0

.0.0.0.1.1.1.0.0.0

CROSSREFS

Sequence in context: A264148 A038001 A147080 * A146011 A104620 A243913

Adjacent sequences:  A146415 A146416 A146417 * A146419 A146420 A146421

KEYWORD

nonn

AUTHOR

R. H. Hardin

STATUS

approved

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Last modified October 22 18:45 EDT 2021. Contains 348175 sequences. (Running on oeis4.)