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A199643
Number of nX4 0..2 arrays with values 0..2 introduced in row major order and each element equal to one or two horizontal and vertical neighbors
1
2, 60, 1265, 29229, 658770, 15066222, 342328663, 7797114144, 177447181083, 4039488090307, 91947444344704, 2092999963213610, 47642308975551650, 1084472533833020100, 24685590900071146822, 561912613968766782369
OFFSET
1,1
COMMENTS
Column 4 of A199647
LINKS
EXAMPLE
Some solutions for n=3
..0..1..1..2....0..1..1..0....0..0..0..0....0..0..1..1....0..0..0..1
..0..1..1..2....0..1..2..0....0..1..1..1....2..2..2..1....1..2..2..1
..2..2..2..2....0..0..2..2....2..2..2..2....2..1..1..1....1..1..1..1
CROSSREFS
Sequence in context: A272980 A222652 A227624 * A056923 A173221 A375840
KEYWORD
nonn
AUTHOR
R. H. Hardin Nov 08 2011
STATUS
approved