%I #10 Nov 24 2018 04:36:24

%S 40,169,646,2359,8298,28450,95628,316568,1035294,3352547,10768211,

%T 34351193,108947285,343813542,1080310949,3381653079,10550153029,

%U 32817177900,101810982442,315106120063,973171192417,2999712678334

%N Number of (1+1) X (n+1) 0..2 arrays with nondecreasing min(x(i,j),x(i,j-1)) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction.

%H R. H. Hardin, <a href="/A250995/b250995.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 6*a(n-1) - 7*a(n-2) - 12*a(n-3) + 15*a(n-4) + 11*a(n-5) - 5*a(n-6) - 3*a(n-7).

%F Empirical g.f.: x*(40 - 71*x - 88*x^2 + 146*x^3 + 94*x^4 - 48*x^5 - 27*x^6) / ((1 + x)*(1 - 3*x)*(1 - x - x^2)*(1 - 3*x + x^3)). - _Colin Barker_, Nov 24 2018

%e Some solutions for n=4:

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

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

%Y Row 1 of A250994.

%K nonn

%O 1,1

%A _R. H. Hardin_, Nov 29 2014