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%I #8 May 19 2023 15:27:56
%S 1,1,114,11734,86954982,329877369234
%N Number of n X n 0..3 arrays with values 0..3 introduced in row major order, the number of instances of each value within one of each other, and every element equal to zero or two horizontal or vertical neighbors.
%C Diagonal of A199201.
%e Some solutions for n=4
%e ..0..1..2..1....0..1..0..2....0..1..0..2....0..1..0..1....0..1..2..0
%e ..3..2..0..2....2..3..2..0....2..0..3..1....1..2..3..0....3..2..1..3
%e ..0..1..3..0....3..1..3..1....3..1..2..0....2..3..0..3....0..1..3..1
%e ..2..3..1..3....2..0..1..3....2..3..1..3....3..2..1..2....2..0..2..3
%Y Cf. A199201.
%K nonn
%O 1,3
%A _R. H. Hardin_, Nov 03 2011