cp's OEIS Frontend

A249702 Number of length n+3 0..3 arrays with every four consecutive terms having the maximum of some two terms equal to the minimum of the remaining two terms.

%I A249702 #6 Jul 23 2025 12:05:57
%S A249702 100,208,440,896,1724,3440,7056,14544,29620,60416,124156,256448,
%T A249702 529304,1091952,2255920,4669824,9673196,20037568,41516752,86070656,
%U A249702 178513920,370298992,768179120,1593817584,3307416676,6864100336,14246134420
%N A249702 Number of length n+3 0..3 arrays with every four consecutive terms having the maximum of some two terms equal to the minimum of the remaining two terms.
%C A249702 Column 3 of A249707
%H A249702 R. H. Hardin, <a href="/A249702/b249702.txt">Table of n, a(n) for n = 1..210</a>
%F A249702 Empirical: a(n) = 2*a(n-1) -a(n-2) +12*a(n-4) -10*a(n-5) -41*a(n-8) -6*a(n-9) -2*a(n-10) +2*a(n-11) +44*a(n-12) +36*a(n-13) +16*a(n-14) -24*a(n-16) -24*a(n-17)
%e A249702 Some solutions for n=6
%e A249702 ..1....1....3....1....0....1....1....1....2....2....1....1....2....0....2....0
%e A249702 ..2....2....2....2....1....1....0....1....2....1....0....1....2....3....2....2
%e A249702 ..2....2....0....2....2....1....2....2....3....2....1....1....2....1....3....3
%e A249702 ..3....2....2....2....1....0....1....1....1....2....1....1....2....1....2....2
%e A249702 ..2....1....2....3....1....2....1....1....2....2....1....3....2....0....2....0
%e A249702 ..2....3....3....0....0....1....1....1....2....2....1....0....2....1....2....2
%e A249702 ..2....2....1....2....1....1....1....1....2....0....1....1....1....1....3....2
%e A249702 ..3....2....2....2....2....1....0....0....3....3....0....1....3....1....2....3
%e A249702 ..0....1....2....2....1....3....3....3....1....2....3....3....2....0....2....2
%K A249702 nonn
%O A249702 1,1
%A A249702 _R. H. Hardin_, Nov 04 2014