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%I #7 Sep 04 2022 22:37:36
%S 648,4050,27378,175232,1131008,7311488,47258642,305390898,1973176200,
%T 12751406208,82400136968,532464529058,3440804225762,22234526147072,
%U 143679727411200,928460232000000,5999721595740450,38770275955862882
%N Number of (n+2) X 4 0..1 arrays with no 3 X 3 subblock having three equal diagonal elements or three equal antidiagonal elements, and new values 0..1 introduced in row major order.
%C Column 2 of A204398.
%H R. H. Hardin, <a href="/A204392/b204392.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = a(n-1) +15*a(n-2) +89*a(n-3) +211*a(n-4) +375*a(n-5) +149*a(n-6) -29*a(n-7) -195*a(n-8) -61*a(n-9) +61*a(n-10) +195*a(n-11) +29*a(n-12) -149*a(n-13) -375*a(n-14) -211*a(n-15) -89*a(n-16) -15*a(n-17) -a(n-18) +a(n-19).
%e Some solutions for n=3
%e ..0..0..1..1....0..0..1..1....0..1..1..1....0..1..0..0....0..1..1..0
%e ..1..1..0..1....0..0..0..0....1..0..0..0....1..0..1..0....1..1..0..1
%e ..0..1..1..1....1..0..1..1....0..1..1..0....1..1..1..0....0..1..0..0
%e ..0..0..0..0....1..1..1..1....0..1..0..0....0..1..0..1....0..1..0..0
%e ..0..0..1..1....0..0..0..1....0..1..0..0....0..1..0..0....0..1..0..1
%Y Cf. A204398.
%K nonn
%O 1,1
%A _R. H. Hardin_, Jan 15 2012
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