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A204749 Number of (n+2) X 5 0..1 arrays with every 3 X 3 subblock having three equal elements in a row horizontally, vertically, diagonally or antidiagonally exactly three ways, and new values 0..1 introduced in row major order. 1

%I

%S 102,31,22,27,35,48,69,103,158,247,391,624,1001,1611,2598,4195,6779,

%T 10960,17725,28671,46382,75039,121407,196432,317825,514243,832054,

%U 1346283,2178323,3524592,5702901,9227479,14930366,24157831,39088183

%N Number of (n+2) X 5 0..1 arrays with every 3 X 3 subblock having three equal elements in a row horizontally, vertically, diagonally or antidiagonally exactly three ways, and new values 0..1 introduced in row major order.

%C Column 3 of A204754.

%H R. H. Hardin, <a href="/A204749/b204749.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) - a(n-3) for n > 5.

%F Empirical g.f.: x*(102 - 173*x - 40*x^2 + 85*x^3 + 12*x^4) / ((1 - x)*(1 - x - x^2)). - _Colin Barker_, Jun 09 2018

%e Some solutions for n=3:

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

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

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

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

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

%Y Cf. A204754.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 18 2012

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Last modified May 18 10:28 EDT 2022. Contains 353807 sequences. (Running on oeis4.)