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A220240
Equals two maps: number of n X 4 binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and vertical neighbors in a random 0..1 n X 4 array.
0
4, 78, 1131, 14976, 219617, 3101079, 43677639, 613533257
OFFSET
1,1
COMMENTS
Column 4 of A220242.
EXAMPLE
Some solutions for n=3
..0..0..1..1....0..0..0..0....0..1..0..0....0..1..0..0....1..1..1..0
..0..0..0..0....1..0..1..1....0..1..0..1....1..0..1..0....0..1..1..0
..1..0..0..0....0..0..0..1....1..0..0..0....0..0..1..0....0..0..1..0
CROSSREFS
Cf. A220242.
Sequence in context: A210519 A279437 A296997 * A246606 A210903 A054951
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 08 2012
STATUS
approved