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 A235276 Number of (n+1) X (6+1) 0..4 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 5 (constant stress 1 X 1 tilings). 1

%I

%S 2800,3844,5096,7936,11704,20440,33464,64168,115480,238024,463736,

%T 1009096,2091544,4737160,10277624,23969608,53719960,127968904,

%U 293325176,709379656,1651106584,4035596680,9490235384,23366392648,55327897240

%N Number of (n+1) X (6+1) 0..4 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 5 (constant stress 1 X 1 tilings).

%H R. H. Hardin, <a href="/A235276/b235276.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = a(n-1) + 15*a(n-2) - 15*a(n-3) - 80*a(n-4) + 80*a(n-5) + 180*a(n-6) - 180*a(n-7) - 144*a(n-8) + 144*a(n-9).

%F Empirical g.f.: 4*x*(700 + 261*x - 10187*x^2 - 3205*x^3 + 52247*x^4 + 12414*x^5 - 111834*x^6 - 15264*x^7 + 83808*x^8) / ((1 - x)*(1 - 2*x)*(1 + 2*x)*(1 - 2*x^2)*(1 - 3*x^2)*(1 - 6*x^2)). - _Colin Barker_, Oct 18 2018

%e Some solutions for n=4:

%e ..0..4..1..4..2..4..0....1..2..0..3..0..3..0....1..4..1..4..1..4..2

%e ..1..0..2..0..3..0..1....4..0..3..1..3..1..3....3..1..3..1..3..1..4

%e ..0..4..1..4..2..4..0....2..3..1..4..1..4..1....1..4..1..4..1..4..2

%e ..1..0..2..0..3..0..1....4..0..3..1..3..1..3....2..0..2..0..2..0..3

%e ..0..4..1..4..2..4..0....1..2..0..3..0..3..0....0..3..0..3..0..3..1

%Y Column 6 of A235280.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 05 2014

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Last modified May 31 07:22 EDT 2020. Contains 334747 sequences. (Running on oeis4.)