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A255075 Number of (n+2) X (1+2) 0..1 arrays with no 3 x 3 subblock diagonal sum one and no antidiagonal sum one. 1

%I

%S 208,676,2444,8836,31960,115600,418200,1512900,5473500,19802500,

%T 71645000,259210000,937825000,3393062500,12276187500,44415562500,

%U 160696875000,581406250000,2103546875000,7610701562500,27535773437500,99625351562500

%N Number of (n+2) X (1+2) 0..1 arrays with no 3 x 3 subblock diagonal sum one and no antidiagonal sum one.

%H R. H. Hardin, <a href="/A255075/b255075.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 5*a(n-1) - 25*a(n-3) + 25*a(n-4) for n>5.

%F Empirical g.f.: 4*x*(52 - 91*x - 234*x^2 + 454*x^3 - 130*x^4) / ((1 - 5*x + 5*x^2)*(1 - 5*x^2)). - _Colin Barker_, Dec 18 2018

%e Some solutions for n=4:

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

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

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

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

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

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

%Y Column 1 of A255082.

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 14 2015

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Last modified October 15 19:49 EDT 2021. Contains 348034 sequences. (Running on oeis4.)