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%I #6 Mar 15 2023 14:49:42
%S 4,2056,291080,43253705,6388528170,944223520057,139549646254609,
%T 20624731224928936,3048237966941788465,450515041275014945368,
%U 66583978433834919848004,9840795003881912664407189
%N Number of n X 4 arrays of occupancy after each element moves to some horizontal, vertical or antidiagonal neighbor.
%C Column 4 of A220943.
%H R. H. Hardin, <a href="/A220941/b220941.txt">Table of n, a(n) for n = 1..14</a>
%e Some solutions for n=3
%e ..0..1..0..1....0..0..0..0....0..2..1..0....0..2..0..3....0..0..0..0
%e ..2..1..1..4....2..4..1..2....0..2..0..0....0..3..1..1....1..5..2..1
%e ..0..1..1..0....1..2..0..0....1..3..3..0....1..1..0..0....0..2..1..0
%Y Cf. A220943.
%K nonn
%O 1,1
%A _R. H. Hardin_, Dec 25 2012