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A220318
Equals two maps: number of n X 4 binary arrays indicating the locations of corresponding elements equal to exactly two of their king-move neighbors in a random 0..2 n X 4 array.
0
4, 89, 3167, 56819, 984087, 16290350, 264901883
OFFSET
1,1
COMMENTS
Column 4 of A220319.
EXAMPLE
Some solutions for n=3
..1..0..0..0....0..0..0..1....1..1..0..0....1..0..1..0....1..0..0..1
..1..0..1..0....1..1..0..0....0..0..1..1....0..1..1..0....0..1..0..0
..0..0..1..0....0..0..0..1....1..0..1..0....0..0..1..0....0..1..1..0
CROSSREFS
Cf. A220319.
Sequence in context: A235858 A262409 A183880 * A220341 A184955 A205295
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 10 2012
STATUS
approved