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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.
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%I #5 Jul 11 2023 15:22:42

%S 4,78,1131,14976,219617,3101079,43677639,613533257

%N 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.

%C Column 4 of A220242.

%e Some solutions for n=3

%e ..0..0..1..1....0..0..0..0....0..1..0..0....0..1..0..0....1..1..1..0

%e ..0..0..0..0....1..0..1..1....0..1..0..1....1..0..1..0....0..1..1..0

%e ..1..0..0..0....0..0..0..1....1..0..0..0....0..0..1..0....0..0..1..0

%Y Cf. A220242.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 08 2012