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Number of nX4 0..1 arrays with no occurrence of three equal elements in a row horizontally, vertically or nw-to-se diagonally, and new values 0..1 introduced in row major order
1

%I #6 Feb 22 2020 20:54:24

%S 5,50,86,265,883,2974,9940,33462,112470,377908,1270638,4271547,

%T 14358358,48270403,162269445,545492694,1833790077,6164622703,

%U 20723502506,69666040146,234195417025,787291729779,2646629705960,8897142589375

%N Number of nX4 0..1 arrays with no occurrence of three equal elements in a row horizontally, vertically or nw-to-se diagonally, and new values 0..1 introduced in row major order

%C Column 4 of A204197

%H R. H. Hardin, <a href="/A204193/b204193.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) +7*a(n-2) +a(n-3) -28*a(n-4) -30*a(n-5) +56*a(n-6) +71*a(n-7) -64*a(n-8) -74*a(n-9) +42*a(n-10) +39*a(n-11) -18*a(n-12) -9*a(n-13) +6*a(n-14) +a(n-15) -a(n-16) for n>19

%e Some solutions for n=5

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Jan 12 2012