cp's OEIS Frontend

A249710 Number of length 4+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 A249710 #8 Nov 10 2018 04:40:21
%S A249710 28,221,896,2601,6172,12789,24032,41937,69052,108493,164000,239993,
%T A249710 341628,474853,646464,864161,1136604,1473469,1885504,2384585,2983772,
%U A249710 3697365,4540960,5531505,6687356,8028333,9575776,11352601,13383356
%N A249710 Number of length 4+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 A249710 R. H. Hardin, <a href="/A249710/b249710.txt">Table of n, a(n) for n = 1..210</a>
%F A249710 Empirical: a(n) = (7/15)*n^5 + 5*n^4 + 11*n^3 + 8*n^2 + (38/15)*n + 1.
%F A249710 Conjectures from _Colin Barker_, Nov 10 2018: (Start)
%F A249710 G.f.: x*(28 + 53*x - 10*x^2 - 20*x^3 + 6*x^4 - x^5) / (1 - x)^6.
%F A249710 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 A249710 (End)
%e A249710 Some solutions for n=6:
%e A249710 ..1....3....4....5....2....1....2....6....6....5....1....2....2....3....2....2
%e A249710 ..3....5....3....0....6....0....3....1....3....3....3....2....4....3....4....3
%e A249710 ..6....1....1....2....3....1....0....1....2....5....3....1....2....5....5....3
%e A249710 ..3....3....3....2....3....1....2....1....3....5....4....2....2....3....4....3
%e A249710 ..3....3....4....2....3....1....2....4....3....5....3....2....1....3....1....4
%e A249710 ..0....3....3....1....3....2....2....1....5....3....3....5....2....3....4....3
%e A249710 ..6....2....2....6....1....0....2....1....1....5....1....1....4....5....6....2
%Y A249710 Row 4 of A249707.
%K A249710 nonn
%O A249710 1,1
%A A249710 _R. H. Hardin_, Nov 04 2014