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A208252 Number of n X n 0..2 arrays with new values 0..2 introduced in row major order and no element equal to more than one of its immediate leftward or upward neighbors.

%I A208252 #9 Jul 22 2025 21:15:00
%S A208252 1,12,2040,2445264,20662697664,1230875651548608,516901401841519506624,
%T A208252 1530268623239822606574667872,31936997040921403605588139690977984,
%U A208252 4698799611233642481043318409392291549604736
%N A208252 Number of n X n 0..2 arrays with new values 0..2 introduced in row major order and no element equal to more than one of its immediate leftward or upward neighbors.
%C A208252 Diagonal of A208258
%H A208252 R. H. Hardin, <a href="/A208252/b208252.txt">Table of n, a(n) for n = 1..13</a>
%e A208252 Some solutions for n=4
%e A208252 ..0..0..0..1....0..0..0..0....0..0..1..2....0..0..0..0....0..0..0..1
%e A208252 ..1..1..0..1....1..0..1..0....0..2..2..0....0..1..0..2....2..1..0..2
%e A208252 ..2..2..1..0....2..2..1..2....2..0..0..1....2..0..1..2....2..0..1..2
%e A208252 ..1..1..0..1....0..0..2..0....2..1..2..1....0..2..1..0....1..0..1..2
%K A208252 nonn
%O A208252 1,2
%A A208252 _R. H. Hardin_ Feb 24 2012