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A208391 Number of nX7 0..2 arrays with new values 0..2 introduced in row major order and no element equal to more than two of its immediate leftward or upward or right-upward antidiagonal neighbors.

%I A208391 #7 Jul 22 2025 21:19:18
%S A208391 365,667476,1233536544,2278687944204,4209452449879284,
%T A208391 7776176148498498768,14365030966055594634024,
%U A208391 26536707847376158191040692,49021604272173916567275685956,90558244799577286285888604547504
%N A208391 Number of nX7 0..2 arrays with new values 0..2 introduced in row major order and no element equal to more than two of its immediate leftward or upward or right-upward antidiagonal neighbors.
%C A208391 Column 7 of A208392
%H A208391 R. H. Hardin, <a href="/A208391/b208391.txt">Table of n, a(n) for n = 1..210</a>
%F A208391 Empirical: a(n) = 1899*a(n-1) -96485*a(n-2) +1863135*a(n-3) -19545624*a(n-4) +128977488*a(n-5) -573780996*a(n-6) +1774673712*a(n-7) -3625252848*a(n-8) +3358392192*a(n-9) +1063196928*a(n-10) for n>12
%e A208391 Some solutions for n=4
%e A208391 ..0..0..0..0..0..0..0....0..1..0..1..1..1..1....0..0..1..1..1..2..1
%e A208391 ..0..1..0..1..2..0..2....1..0..0..0..1..2..1....1..1..2..1..0..1..2
%e A208391 ..1..0..2..1..2..1..2....0..2..1..0..2..2..1....1..2..0..1..2..1..2
%e A208391 ..2..1..2..0..2..2..2....0..2..2..2..1..2..0....0..0..1..0..2..0..1
%K A208391 nonn
%O A208391 1,1
%A A208391 _R. H. Hardin_ Feb 25 2012