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%I #7 May 28 2021 12:39:05
%S 256,2120,17920,151824,1285076,10876432,92062852,779221408,6595612052,
%T 55825506424,472525827000,3999488656608,33852918814560,
%U 286533994691184,2425307371380272,20528052539179312,173755089791996132
%N Number of (n+1) X 2 0..3 arrays with the number of clockwise edge increases in every 2 X 2 subblock differing from each horizontal or vertical neighbor.
%C Column 1 of A205466.
%H R. H. Hardin, <a href="/A205459/b205459.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 63*a(n-2) +50*a(n-3) +190*a(n-4) +42*a(n-5) +57*a(n-6) +122*a(n-7) +39*a(n-8) -12*a(n-9) for n > 10.
%e Some solutions for n=4
%e ..3..1....2..0....2..0....1..0....1..2....1..1....1..3....1..3....3..1....2..2
%e ..1..3....2..3....1..2....0..1....0..1....2..0....3..3....1..3....1..1....1..0
%e ..2..2....3..0....1..1....0..0....0..0....2..1....2..0....3..1....3..2....0..0
%e ..1..3....2..1....0..2....3..2....0..0....1..1....0..0....1..1....3..0....0..0
%e ..1..2....2..3....1..1....1..1....3..0....3..2....2..1....0..2....1..1....1..1
%Y Cf. A205466.
%K nonn
%O 1,1
%A _R. H. Hardin_ Jan 27 2012
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