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A208406 Number of nX6 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 right-upward antidiagonal neighbors.

%I A208406 #7 Jul 22 2025 21:20:03
%S A208406 187,658450,2540446156,9810325806914,37884515848419250,
%T A208406 146298576850884166522,564960990903273888822194,
%U A208406 2181708996196484728947116626,8425102300382037852914721068050
%N A208406 Number of nX6 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 right-upward antidiagonal neighbors.
%C A208406 Column 6 of A208408
%H A208406 R. H. Hardin, <a href="/A208406/b208406.txt">Table of n, a(n) for n = 1..210</a>
%F A208406 Empirical: a(n) = 3934*a(n-1) -280797*a(n-2) +6155504*a(n-3) -54994340*a(n-4) +272040900*a(n-5) -839264272*a(n-6) +1746698176*a(n-7) -2573895744*a(n-8) +2742227712*a(n-9) -2077701120*a(n-10) +970113024*a(n-11) -191102976*a(n-12) for n>13
%e A208406 Some solutions for n=4
%e A208406 ..0..0..0..0..0..0....0..1..1..0..0..0....0..1..0..0..2..2....0..0..0..0..0..0
%e A208406 ..1..2..1..0..1..3....0..1..1..0..2..1....1..2..1..1..3..2....0..1..1..0..2..1
%e A208406 ..1..3..3..1..1..3....1..2..0..3..2..3....0..3..3..0..1..3....0..1..0..2..2..1
%e A208406 ..0..1..0..0..1..0....3..0..0..2..1..3....2..1..1..2..1..1....0..3..1..0..1..0
%K A208406 nonn
%O A208406 1,1
%A A208406 _R. H. Hardin_ Feb 26 2012