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A228500 Number of n X n binary arrays with top left value 1 and no two ones adjacent horizontally, vertically, diagonally or antidiagonally. 1
1, 1, 12, 87, 2002, 59839, 3862849, 405580157, 81304395949, 28446567810005, 18268841726936268, 20937720031330292269, 43502129718103134992611, 162426195975365708781849519, 1095156092719874995442597502324 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
COMMENTS
Diagonal of A228506
LINKS
EXAMPLE
Some solutions for n=4
..1..0..0..1....1..0..0..1....1..0..0..0....1..0..1..0....1..0..0..0
..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..1
..1..0..0..1....0..1..0..1....0..0..0..0....0..0..1..0....0..0..0..0
..0..0..0..0....0..0..0..0....0..1..0..0....1..0..0..0....0..0..0..1
CROSSREFS
Sequence in context: A180797 A137207 A206765 * A348415 A082814 A178257
KEYWORD
nonn
AUTHOR
R. H. Hardin Aug 23 2013
STATUS
approved

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Last modified July 19 02:27 EDT 2024. Contains 374388 sequences. (Running on oeis4.)