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Number of length n+3 0..6 arrays with no four elements in a row with pattern abba (with a!=b) and new values 0..6 introduced in 0..6 order.
1

%I #6 May 07 2022 22:03:20

%S 14,46,174,737,3434,17366,94164,541060,3257286,20333069,130439432,

%T 853756157,5669606647,38041540586,257118895765,1746784622435,

%U 11909889453316,81408594286227,557440239347213,3821747622458620

%N Number of length n+3 0..6 arrays with no four elements in a row with pattern abba (with a!=b) and new values 0..6 introduced in 0..6 order.

%C Column 6 of A243389.

%H R. H. Hardin, <a href="/A243387/b243387.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 22*a(n-1) -195*a(n-2) +914*a(n-3) -2539*a(n-4) +4594*a(n-5) -6074*a(n-6) +6382*a(n-7) -5368*a(n-8) +3726*a(n-9) -2167*a(n-10) +1026*a(n-11) -419*a(n-12) +130*a(n-13) -36*a(n-14) +6*a(n-15) -a(n-16).

%e Some solutions for n=3

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

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

%e ..0....1....1....2....1....0....0....1....1....0....2....1....2....0....0....2

%e ..2....2....2....3....2....1....2....1....1....0....3....2....3....2....0....1

%e ..1....1....1....4....0....2....3....0....2....0....0....2....2....0....2....2

%e ..0....3....0....1....2....2....2....2....1....1....1....2....0....2....0....3

%Y Cf. A243389.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jun 04 2014