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A251082 Number of (n+1) X (2+1) 0..2 arrays with no 2 X 2 subblock having the sum of its diagonal elements greater than the absolute difference of its antidiagonal elements. 1

%I

%S 83,284,616,1306,2534,4848,9086,17102,32336,61836,119420,232882,

%T 457522,904088,1793778,3569126,7114892,14200724,28365600,56687594,

%U 113322526,226582144,453089606,906091326,1812079784,3624040028,7247941796

%N Number of (n+1) X (2+1) 0..2 arrays with no 2 X 2 subblock having the sum of its diagonal elements greater than the absolute difference of its antidiagonal elements.

%H R. H. Hardin, <a href="/A251082/b251082.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 6*a(n-1) - 13*a(n-2) + 10*a(n-3) + 5*a(n-4) - 14*a(n-5) + 9*a(n-6) - 2*a(n-7) for n>8.

%F Empirical g.f.: x*(83 - 214*x - 9*x^2 + 472*x^3 - 549*x^4 + 204*x^5 + 29*x^6 - 26*x^7) / ((1 - x)^5*(1 + x)*(1 - 2*x)). - _Colin Barker_, Nov 24 2018

%e Some solutions for n=4:

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

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

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

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

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

%Y Column 2 of A251088.

%K nonn

%O 1,1

%A _R. H. Hardin_, Nov 29 2014

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Last modified January 30 19:55 EST 2023. Contains 359947 sequences. (Running on oeis4.)