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%I #8 Nov 01 2018 12:24:35
%S 14,46,163,602,2271,8655,33148,127255,489084,1880732,7234069,27828644,
%T 107059965,411883517,1584628966,6096542009,23455294538,90239951178,
%U 347181934423,1335720317278,5138945540059,19771177361419,76066085076416
%N Number of length n+3 0..3 arrays with no four elements in a row with pattern abab (with a!=b) and new values 0..3 introduced in 0..3 order.
%H R. H. Hardin, <a href="/A243039/b243039.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 5*a(n-1) - 3*a(n-2) - 5*a(n-3) - 3*a(n-4) + 3*a(n-5) + 3*a(n-6) + a(n-7).
%F Empirical g.f.: x*(14 - 24*x - 25*x^2 - 5*x^3 + 22*x^4 + 17*x^5 + 5*x^6) / ((1 - x)*(1 - x - x^2 - x^3)*(1 - 3*x - 3*x^2 - x^3)). - _Colin Barker_, Nov 01 2018
%e Some solutions for n=4:
%e ..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
%e ..1....1....0....1....1....1....0....1....1....1....1....1....1....0....0....1
%e ..2....2....1....1....2....2....0....0....2....2....2....2....1....0....1....0
%e ..3....1....2....2....1....0....1....2....1....2....0....2....0....0....0....0
%e ..0....3....3....3....0....0....1....2....1....2....2....2....2....1....2....2
%e ..3....1....1....3....3....3....2....2....1....3....1....0....0....2....3....1
%e ..2....2....0....0....0....3....2....1....2....2....0....2....1....1....0....2
%Y Column 3 of A243044.
%K nonn
%O 1,1
%A _R. H. Hardin_, May 29 2014
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