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%I #8 Jun 07 2018 08:28:38
%S 51,48,54,63,88,128,193,300,470,747,1196,1920,3093,4992,8062,13031,
%T 21072,34080,55129,89188,144294,233459,377732,611168,988877,1600024,
%U 2588878,4188879,6777736,10966592,17744305,28710876,46455158,75166011,121621148
%N Number of (n+2) X 4 0..1 arrays with every 3 X 3 subblock having three equal elements in a row horizontally, vertically or nw-to-se diagonally exactly three ways, and new values 0..1 introduced in row major order.
%C Column 2 of A204381.
%H R. H. Hardin, <a href="/A204375/b204375.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = a(n-1) +a(n-2) +a(n-3) -a(n-4) -a(n-5) for n>8.
%F Empirical g.f.: x*(51 - 3*x - 45*x^2 - 90*x^3 - 26*x^4 + 22*x^5 + 16*x^6 + 8*x^7) / ((1 - x)*(1 - x - x^2)*(1 + x + x^2)). - _Colin Barker_, Jun 07 2018
%e Some solutions for n=3:
%e ..0..1..1..1....0..0..0..0....0..0..0..1....0..0..1..0....0..0..0..1
%e ..0..0..1..1....0..0..0..0....1..1..0..1....0..0..1..0....1..1..1..1
%e ..0..0..0..1....1..1..1..1....0..0..0..0....0..0..1..0....1..1..1..1
%e ..1..0..0..0....0..0..0..0....0..0..0..0....0..0..1..0....0..0..0..0
%e ..0..1..0..0....0..0..0..0....1..1..1..1....0..0..1..0....1..1..1..1
%Y Cf. A204381.
%K nonn
%O 1,1
%A _R. H. Hardin_, Jan 14 2012
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