A250772 - OEIS

%I #8 Nov 19 2018 07:19:00

%S 72,130,216,350,572,962,1680,3046,5700,10922,21272,41870,82956,165010,

%T 328992,656822,1312340,2623226,5244840,10487902,20973852,41945570,

%U 83888816,167775110,335547492,671092042,1342180920,2684358446,5368713260

%N Number of (4+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="/A250772/b250772.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) = 20*2^(n-1) + 4*n^2 + 26*n + 22.

%F Empirical g.f.: 2*x*(36 - 115*x + 107*x^2 - 32*x^3) / ((1 - x)^3*(1 - 2*x)). - _Colin Barker_, Nov 19 2018

%e Some solutions for n=4:

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

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

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

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

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

%Y Row 4 of A250769.

%K nonn

%O 1,1

%A _R. H. Hardin_, Nov 27 2014