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%I #7 Aug 21 2017 05:59:10
%S 6,514,9480,82398,457366,1886948,6308960,18038628,45704886,105193902,
%T 223903240,446650386,843619686,1520772064,2633182208,4401808232,
%U 7134239142,11250005754,17311081032,26058236134,38453958774,55732680828
%N Number of length 5+3 0..n arrays with no four consecutive terms having the maximum of any two terms equal to the minimum of the remaining two terms.
%C Row 5 of A250387.
%H R. H. Hardin, <a href="/A250391/b250391.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = n^8 + (1/5)*n^7 + (563/180)*n^6 + (19/30)*n^5 + (1/9)*n^4 + (9/5)*n^3 - (223/180)*n^2 + (11/30)*n.
%F Conjectures from _Colin Barker_, Aug 21 2017: (Start)
%F G.f.: 2*x*(3 + 230*x + 2535*x^2 + 7539*x^3 + 7322*x^4 + 2335*x^5 + 196*x^6) / (1 - x)^9.
%F a(n) = 9*a(n-1) - 36*a(n-2) + 84*a(n-3) - 126*a(n-4) + 126*a(n-5) - 84*a(n-6) + 36*a(n-7) - 9*a(n-8) + a(n-9) for n>9.
%F (End)
%e Some solutions for n=4:
%e ..1....2....0....1....0....3....2....1....4....0....1....4....1....3....0....3
%e ..2....2....1....4....3....2....2....2....3....3....0....3....4....4....3....0
%e ..0....1....0....1....2....0....3....4....1....1....4....1....2....1....2....2
%e ..2....1....4....3....1....1....3....1....1....2....3....0....1....4....1....4
%e ..1....4....3....0....4....0....0....4....3....1....2....4....0....3....0....1
%e ..0....3....4....0....3....3....0....2....3....4....1....2....2....2....2....4
%e ..2....2....0....2....1....4....3....3....1....0....3....3....0....4....4....2
%e ..2....2....0....1....4....0....2....4....2....0....0....2....3....4....0....4
%K nonn
%O 1,1
%A _R. H. Hardin_, Nov 20 2014
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