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A234754 Number of (n+1)X(2+1) 0..3 arrays with 2X2 edge jumps all no more than +1 in one of the clockwise or counterclockwise directions or both.

%I A234754 #6 Jul 23 2025 08:23:56
%S A234754 1014,26642,646036,15939010,392044622,9648827736,237446135146,
%T A234754 5843394219306,143801532689336,3538850266550630,87088497253969902,
%U A234754 2143183802626938104,52742175287648016058,1297946099417129620238
%N A234754 Number of (n+1)X(2+1) 0..3 arrays with 2X2 edge jumps all no more than +1 in one of the clockwise or counterclockwise directions or both.
%C A234754 Column 2 of A234760
%H A234754 R. H. Hardin, <a href="/A234754/b234754.txt">Table of n, a(n) for n = 1..210</a>
%F A234754 Empirical: a(n) = 27*a(n-1) -26*a(n-2) -884*a(n-3) +1597*a(n-4) +7345*a(n-5) -14758*a(n-6) -23881*a(n-7) +52625*a(n-8) +29984*a(n-9) -81577*a(n-10) -7015*a(n-11) +51495*a(n-12) -7850*a(n-13) -9139*a(n-14) +1340*a(n-15) +518*a(n-16) -36*a(n-17)
%e A234754 Some solutions for n=2
%e A234754 ..3..2..3....2..1..0....1..2..1....0..2..0....0..1..1....3..2..1....3..1..3
%e A234754 ..0..1..2....1..1..1....2..2..1....1..1..1....2..2..3....1..2..3....2..2..2
%e A234754 ..1..0..1....1..1..0....3..2..3....0..2..1....0..1..1....0..1..1....3..1..0
%K A234754 nonn
%O A234754 1,1
%A A234754 _R. H. Hardin_, Dec 30 2013