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A146017 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 2X4 el 1,1 1,2 1,3 1,4 2,4 with any orientation. 0
1, 1, 1, 1, 1, 1, 1, 1, 29, 29, 297, 297, 3639, 3639, 84611, 84611, 2861167, 2861167, 210769267, 210769267, 22904472355, 22904472355 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,9

LINKS

Table of n, a(n) for n=1..22.

EXAMPLE

Maximal 9 X 9 example

.1.0.1.1.0.1.1.0.1

.1.0.0.1.0.1.0.0.1

.1.0.0.1.0.1.0.0.1

.1.1.0.1.0.1.0.1.1

.0.0.0.0.0.0.0.0.0

.1.1.0.1.0.1.0.1.1

.1.0.0.1.0.1.0.0.1

.1.0.0.1.0.1.0.0.1

.1.0.1.1.0.1.1.0.1

CROSSREFS

Sequence in context: A146423 A146129 A146040 * A210267 A210309 A165850

Adjacent sequences:  A146014 A146015 A146016 * A146018 A146019 A146020

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 26 2008

STATUS

approved

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Last modified October 23 01:49 EDT 2020. Contains 337962 sequences. (Running on oeis4.)