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A208194 Number of n X n 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than two of its immediate leftward or upward or left-upward diagonal neighbors.

%I A208194 #9 Jul 22 2025 21:14:09
%S A208194 1,14,10366,156617480,37069738362057,136398703432330477549,
%T A208194 7801822458198433796561428608,6937084083184530563330081968289999750,
%U A208194 95885498147917477608538934758547979039384601906
%N A208194 Number of n X n 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than two of its immediate leftward or upward or left-upward diagonal neighbors.
%C A208194 Diagonal of A208201
%H A208194 R. H. Hardin, <a href="/A208194/b208194.txt">Table of n, a(n) for n = 1..10</a>
%e A208194 Some solutions for n=4
%e A208194 ..0..1..0..0....0..0..0..0....0..0..0..1....0..0..1..0....0..0..1..2
%e A208194 ..2..0..3..0....1..1..1..1....1..2..1..1....0..2..2..0....0..3..3..0
%e A208194 ..2..0..3..1....2..1..2..3....0..2..0..3....2..3..3..0....1..0..1..2
%e A208194 ..1..2..0..2....0..1..2..0....0..0..2..1....1..2..3..2....1..1..0..0
%K A208194 nonn
%O A208194 1,2
%A A208194 _R. H. Hardin_ Feb 24 2012