%I #5 Jan 17 2013 08:32:37
%S 0,1,2,7,25,102,456,2219,11640,65364,390646,2472719,16508791,
%T 115839661,851634863,6542134884,52384882759,436290809772,
%U 3772143122161,33797290492507,313304547351868,3000631062271288,29651208549845055
%N Number of 0..n arrays of length n with each element unequal to at least one neighbor, with new values introduced in 0..n order
%C Diagonal of A221459
%H R. H. Hardin, <a href="/A221453/b221453.txt">Table of n, a(n) for n = 1..182</a>
%e Some solutions for n=6
%e ..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
%e ..1....1....1....1....1....1....1....1....1....1....1....1....1....1....1....1
%e ..0....2....1....0....2....2....1....0....2....2....0....1....0....1....1....1
%e ..2....1....2....1....3....0....2....2....1....3....2....2....1....2....2....0
%e ..2....3....1....1....0....0....2....3....2....2....1....2....2....1....3....0
%e ..3....4....2....2....3....3....1....0....3....0....2....0....0....3....0....1
%K nonn
%O 1,3
%A _R. H. Hardin_ Jan 17 2013
