A244694 - OEIS

%I #8 Nov 03 2018 10:32:19

%S 39,111,317,908,2602,7459,21383,61302,175745,503841,1444456,4141097,

%T 11872072,34035934,97577307,279743489,801994051,2299229415,6591639797,

%U 18897511895,54177104154,155319844796,445285043640,1276583622333

%N Number of length n+4 0..2 arrays with no five consecutive elements with pattern ababa or abbba (with a!=b) and new values 0..2 introduced in 0..2 order.

%H R. H. Hardin, <a href="/A244694/b244694.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) - a(n-3) - a(n-5) + a(n-6) - a(n-7).

%F Empirical g.f.: x*(39 - 6*x - 16*x^2 - 4*x^3 - 11*x^4 + 9*x^5 - 14*x^6) / ((1 - x)*(1 + x)*(1 - 3*x + x^2 - 2*x^3 + x^4 - x^5)). - _Colin Barker_, Nov 03 2018

%e Some solutions for n=6:

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

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

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

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

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

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

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

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

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

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

%Y Column 2 of A244702.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jul 04 2014