A250774 - OEIS

%I #8 Nov 19 2018 09:13:45

%S 288,514,820,1234,1812,2666,4020,6322,10468,18250,33252,62642,120756,

%T 236266,466516,926194,1844676,3680714,7351812,14692978,29374228,

%U 58735594,117457140,234898994,469781412,939544906,1879070500,3758120242

%N Number of (6+1) X (n+1) 0..1 arrays with nondecreasing 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="/A250774/b250774.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); a(n) = 28*2^(n-1) + 26*n^2 + 120*n + 114.

%F Empirical g.f.: 2*x*(144 - 463*x + 421*x^2 - 128*x^3) / ((1 - x)^3*(1 - 2*x)). - _Colin Barker_, Nov 19 2018

%e Some solutions for n=4:

%e ..0..0..0..0..0....1..0..0..0..0....1..0..0..0..0....0..0..1..1..0

%e ..1..1..1..1..1....1..1..1..1..1....1..0..0..0..0....0..0..1..1..0

%e ..1..1..1..1..1....0..0..0..0..0....1..1..1..1..1....0..0..1..1..0

%e ..1..1..1..1..1....1..1..1..1..1....0..0..0..0..0....0..0..1..1..0

%e ..1..1..1..1..1....0..0..0..0..0....1..1..1..1..1....0..0..1..1..1

%e ..0..0..0..0..0....0..0..0..0..0....0..0..0..0..0....0..0..1..1..1

%e ..0..0..0..1..1....0..0..0..1..1....0..0..0..0..0....0..0..1..1..1

%Y Row 6 of A250769.

%K nonn

%O 1,1

%A _R. H. Hardin_, Nov 27 2014