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A238317 Number of (n+1)X(2+1) 0..2 arrays with no element greater than all horizontal neighbors or less than all vertical neighbors.

%I A238317 #6 Jul 23 2025 10:51:37
%S A238317 9,67,376,1867,9489,50232,267174,1408341,7395987,38886701,204722786,
%T A238317 1077853232,5673085286,29856142160,157133586571,827031030519,
%U A238317 4352855509300,22909846720541,120578232671314,634623931681625
%N A238317 Number of (n+1)X(2+1) 0..2 arrays with no element greater than all horizontal neighbors or less than all vertical neighbors.
%C A238317 Column 2 of A238323
%H A238317 R. H. Hardin, <a href="/A238317/b238317.txt">Table of n, a(n) for n = 1..210</a>
%F A238317 Empirical: a(n) = 6*a(n-1) -12*a(n-2) +39*a(n-3) +6*a(n-4) +62*a(n-5) +49*a(n-6) +33*a(n-7) -32*a(n-8) -41*a(n-9) -12*a(n-10) +6*a(n-11) +5*a(n-12) +a(n-13)
%e A238317 Some solutions for n=5
%e A238317 ..2..2..1....1..1..1....0..1..1....1..1..1....2..2..2....1..2..2....0..2..2
%e A238317 ..1..1..1....1..1..1....0..0..0....0..0..0....0..0..0....0..0..0....0..2..2
%e A238317 ..1..1..1....2..2..0....0..0..0....0..0..0....0..0..0....0..0..0....2..2..1
%e A238317 ..1..1..0....1..1..0....0..2..2....2..2..0....0..0..0....0..1..1....0..0..0
%e A238317 ..1..1..0....0..1..1....0..2..2....2..2..2....0..1..1....1..2..2....0..0..0
%e A238317 ..1..2..2....0..2..2....0..2..2....2..2..2....1..1..1....2..2..2....2..2..1
%K A238317 nonn
%O A238317 1,1
%A A238317 _R. H. Hardin_, Feb 24 2014