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A144059 Number of n X n binary arrays, symmetric under 180 degree rotation, with every 1 adjacent to at least one other 1, but at most one 1 adjacent horizontally and at most one 1 adjacent vertically. 0
1, 2, 7, 43, 317, 4395, 85883, 3189035, 155707292, 14992855085, 1844750664909, 446183107764907, 140966932321586720 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

CROSSREFS

Sequence in context: A091877 A050631 A146759 * A078676 A086331 A121418

Adjacent sequences:  A144056 A144057 A144058 * A144060 A144061 A144062

KEYWORD

nonn

AUTHOR

R. H. Hardin (rhhardin(AT)att.net), Sep 08 2008

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Last modified February 16 09:00 EST 2012. Contains 205904 sequences.