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A265451 Number of n X 1 0..n+1-2 arrays with each element differing from its horizontal and vertical neighbors by one or two.

%I A265451 #11 Oct 25 2022 20:30:16
%S A265451 1,1,2,12,66,360,1864,9358,45642,217590,1017626,4684896,21284488,
%T A265451 95624666,425523864,1878025074,8229470812,35836393568,155196577484,
%U A265451 668832795812,2869861291134,12266161148622,52243167132940,221803857150698,938974990229088,3964558585350392
%N A265451 Number of n X 1 0..n+1-2 arrays with each element differing from its horizontal and vertical neighbors by one or two.
%H A265451 Alois P. Heinz, <a href="/A265451/b265451.txt">Table of n, a(n) for n = 0..500</a> (terms n = 1..210 from R. H. Hardin)
%e A265451 Some solutions for n=4
%e A265451 ..3....3....1....2....2....0....3....0....0....1....2....2....1....0....0....3
%e A265451 ..2....1....2....0....1....1....1....1....2....3....3....0....0....1....1....2
%e A265451 ..3....2....1....2....0....3....0....0....1....2....2....1....1....3....2....0
%e A265451 ..2....1....3....1....1....2....1....1....0....1....0....2....2....1....0....2
%Y A265451 Column 1 of A265458.
%Y A265451 Cf. A102699.
%K A265451 nonn
%O A265451 0,3
%A A265451 _R. H. Hardin_, Dec 09 2015
%E A265451 a(0)=1 prepended by _Alois P. Heinz_, Oct 25 2022