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%I #6 Apr 20 2020 19:41:08
%S 1,1,4,5,29,78,466,3907,52773,925875,25789942
%N Number of n X n integer arrays with each element equal to the number of horizontal and vertical neighbors differing from itself by exactly one.
%C Diagonal of A266081.
%e All solutions for n=4
%e ..0..2..3..2....0..0..0..0....0..0..0..0....2..3..2..0....0..0..0..0
%e ..0..3..4..3....2..3..2..0....0..0..0..0....3..4..3..0....0..2..3..2
%e ..0..2..3..2....3..4..3..0....0..0..0..0....2..3..2..0....0..3..4..3
%e ..0..0..0..0....2..3..2..0....0..0..0..0....0..0..0..0....0..2..3..2
%Y Cf. A266081.
%K nonn
%O 1,3
%A _R. H. Hardin_, Dec 20 2015