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A146004 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 3X3 plus 2,1 2,2 2,3 1,2 3,2. 0
1, 1, 2, 1, 4, 7, 21, 46, 195, 635, 3736, 16722, 140702, 874897, 10218521, 89150959, 1456627028, 17686096248, 403908679949, 6882785245717, 219237062845023, 5210440958351021, 232082441606979544, 7714095184686817142 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..24.

EXAMPLE

Maximal 8 X 8 example

.0.0.0.0.0.0.1.0

.0.0.0.0.0.1.1.1

.0.0.1.0.0.0.1.0

.0.1.1.1.0.1.0.0

.0.0.1.0.1.1.1.0

.0.1.0.0.0.1.0.0

.1.1.1.0.0.0.0.0

.0.1.0.0.0.0.0.0

CROSSREFS

Sequence in context: A184345 A045625 A294501 * A001933 A038557 A011234

Adjacent sequences:  A146001 A146002 A146003 * A146005 A146006 A146007

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 26 2008

STATUS

approved

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Last modified April 5 11:18 EDT 2020. Contains 333239 sequences. (Running on oeis4.)