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A208197 Number of nX4 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 A208197 #7 Jul 22 2025 21:14:16
%S A208197 15,2653,639701,156617480,38372808893,9402035642924,2303673397508915,
%T A208197 564442821781056268,138298988287411669755,33885824084409470445384,
%U A208197 8302657077306720410135797,2034305388933816797435987804
%N A208197 Number of nX4 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 A208197 Column 4 of A208201
%H A208197 R. H. Hardin, <a href="/A208197/b208197.txt">Table of n, a(n) for n = 1..210</a>
%F A208197 Empirical: a(n) = 236*a(n-1) +2368*a(n-2) -37526*a(n-3) -310734*a(n-4) +811712*a(n-5) +1791667*a(n-6) -2516274*a(n-7) -1895184*a(n-8) +2138400*a(n-9) -373248*a(n-10) for n>11
%e A208197 Some solutions for n=4
%e A208197 ..0..0..0..1....0..0..0..1....0..1..1..0....0..0..0..1....0..0..0..0
%e A208197 ..0..1..1..0....1..1..0..0....0..0..2..0....0..1..0..2....0..1..1..2
%e A208197 ..0..1..2..3....2..3..3..0....0..2..1..1....2..1..0..3....1..0..1..3
%e A208197 ..3..0..3..1....0..2..1..3....3..1..0..0....1..0..1..0....1..3..3..1
%K A208197 nonn
%O A208197 1,1
%A A208197 _R. H. Hardin_ Feb 24 2012