

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




OFFSET

1,1


COMMENTS



LINKS



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



KEYWORD

nonn


AUTHOR



STATUS

approved



