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A146069 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 5-point zee 1,1 2,1 2,2 2,3 3,3 in any orientation. 0
1, 1, 1, 1, 1, 1, 9, 21, 35, 101, 287, 859, 3329, 15189, 75035, 399377, 2204921, 14787995, 102936591, 860535039, 7743744003, 81593423043, 911784626279 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,7

LINKS

Table of n, a(n) for n=1..23.

EXAMPLE

Maximal 8 X 8 example

.1.0.0.0.0.0.1.1

.1.1.1.0.0.0.1.0

.0.0.1.0.0.1.1.0

.0.0.0.0.0.0.0.0

.0.0.0.0.0.0.0.0

.0.1.1.0.0.1.0.0

.0.1.0.0.0.1.1.1

.1.1.0.0.0.0.0.1

CROSSREFS

Sequence in context: A253052 A043112 A043892 * A140673 A186294 A059993

Adjacent sequences:  A146066 A146067 A146068 * A146070 A146071 A146072

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 26 2008

STATUS

approved

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Last modified November 18 14:15 EST 2017. Contains 294893 sequences.