%I #7 Nov 15 2018 08:38:22
%S 26,64,140,290,586,1172,2336,4654,9278,18512,36964,73850,147602,
%T 295084,590024,1179878,2359558,4718888,9437516,18874738,37749146,
%U 75497924,150995440,301990430,603980366,1207960192,2415919796,4831838954
%N Number of (n+1) X (2+1) 0..1 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing x(i,j)-x(i-1,j) in the j direction.
%H R. H. Hardin, <a href="/A250605/b250605.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 5*a(n-1) - 9*a(n-2) + 7*a(n-3) - 2*a(n-4).
%F Empirical: a(n) = 36*2^(n-1) + n^2 - n - 10.
%F Empirical g.f.: 2*x*(13 - 33*x + 27*x^2 - 8*x^3) / ((1 - x)^3*(1 - 2*x)). - _Colin Barker_, Nov 15 2018
%e Some solutions for n=6:
%e ..1..0..0....1..1..0....1..1..1....0..0..0....1..0..0....1..0..0....0..0..0
%e ..1..1..1....0..0..0....0..0..0....0..0..0....0..0..0....1..0..0....1..1..1
%e ..1..1..1....0..0..0....0..0..0....1..1..1....1..1..1....0..0..0....0..0..0
%e ..0..0..1....0..0..0....1..1..1....0..0..0....1..1..1....1..1..1....1..1..1
%e ..0..0..1....1..1..1....1..1..1....0..0..0....0..0..1....1..1..1....0..0..1
%e ..0..0..1....1..1..1....0..1..1....0..0..0....0..0..1....1..1..1....0..0..1
%e ..0..0..1....1..1..1....0..1..1....1..1..1....0..0..1....0..1..1....0..0..1
%Y Column 2 of A250611.
%K nonn
%O 1,1
%A _R. H. Hardin_, Nov 26 2014