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A234486 Number of (n+1)X(4+1) 0..3 arrays with every 2X2 subblock having its diagonal sum differing from its antidiagonal sum by 2 (constant stress 1X1 tilings) 1

%I

%S 3686,13554,49784,183422,677138,2505400,9288710,34509914,128461544,

%T 479146446,1790472578,6703375016,25141441190,94466340970,355552667288,

%U 1340563920974,5062700401010,19151478723096,72561523035974

%N Number of (n+1)X(4+1) 0..3 arrays with every 2X2 subblock having its diagonal sum differing from its antidiagonal sum by 2 (constant stress 1X1 tilings)

%C Column 4 of A234490

%H R. H. Hardin, <a href="/A234486/b234486.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 16*a(n-1) -69*a(n-2) -186*a(n-3) +2233*a(n-4) -3610*a(n-5) -15789*a(n-6) +56088*a(n-7) +1729*a(n-8) -189898*a(n-9) +95019*a(n-10) +304674*a(n-11) -145486*a(n-12) -269396*a(n-13) +58980*a(n-14) +118584*a(n-15) +6480*a(n-16) -16992*a(n-17) -3456*a(n-18)

%e Some solutions for n=4

%e ..2..0..2..3..2....2..1..2..2..3....0..3..0..3..3....2..1..1..0..1

%e ..1..1..1..0..1....0..1..0..2..1....2..3..2..3..1....2..3..1..2..1

%e ..3..1..3..0..3....2..1..2..2..3....1..0..1..0..0....3..2..2..1..2

%e ..2..2..2..1..2....2..3..2..0..3....2..3..2..3..1....0..1..3..0..3

%e ..2..0..2..3..2....2..1..2..2..3....0..3..0..3..3....2..1..1..0..1

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 26 2013

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Last modified August 25 09:48 EDT 2019. Contains 326324 sequences. (Running on oeis4.)