cp's OEIS Frontend

A249711 Number of length 5+3 0..n arrays with every four consecutive terms having the maximum of some two terms equal to the minimum of the remaining two terms.

%I A249711 #8 Nov 10 2018 04:40:17
%S A249711 38,377,1724,5425,13666,29673,57912,104289,176350,283481,437108,
%T A249711 650897,940954,1326025,1827696,2470593,3282582,4294969,5542700,
%U A249711 7064561,8903378,11106217,13724584,16814625,20437326,24658713,29550052,35188049,41655050
%N A249711 Number of length 5+3 0..n arrays with every four consecutive terms having the maximum of some two terms equal to the minimum of the remaining two terms.
%H A249711 R. H. Hardin, <a href="/A249711/b249711.txt">Table of n, a(n) for n = 1..210</a>
%F A249711 Empirical: a(n) = (5/3)*n^5 + 10*n^4 + 16*n^3 + 8*n^2 + (4/3)*n + 1.
%F A249711 Conjectures from _Colin Barker_, Nov 10 2018: (Start)
%F A249711 G.f.: x*(38 + 149*x + 32*x^2 - 24*x^3 + 6*x^4 - x^5) / (1 - x)^6.
%F A249711 a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>6.
%F A249711 (End)
%e A249711 Some solutions for n=6:
%e A249711 ..0....2....1....1....0....2....5....4....0....5....2....3....0....6....3....4
%e A249711 ..1....2....5....5....4....5....2....4....3....2....2....3....2....0....3....2
%e A249711 ..5....0....6....6....3....3....3....6....5....6....2....3....2....2....3....1
%e A249711 ..1....6....5....5....3....3....3....4....3....5....6....6....4....2....1....2
%e A249711 ..0....2....5....5....3....3....5....4....1....5....1....1....2....2....3....2
%e A249711 ..1....2....5....5....0....0....3....0....3....5....2....3....2....2....5....2
%e A249711 ..6....2....4....4....6....3....2....4....3....3....2....3....1....1....3....3
%e A249711 ..1....2....5....6....3....5....3....5....5....5....3....6....6....5....3....1
%Y A249711 Row 5 of A249707.
%K A249711 nonn
%O A249711 1,1
%A A249711 _R. H. Hardin_, Nov 04 2014