A250794 Number of (n+1) X (5+1) 0..1 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.

252, 838, 2776, 9258, 31220, 105954, 361344, 1236058, 4237556, 14549610, 50012080, 172050098, 592248148, 2039649282, 7026884288, 24215293674, 83465955764, 287740551770, 992085339216, 3420905014178, 11796889975188, 40683768017330

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 10*a(n-1) - 33*a(n-2) + 24*a(n-3) + 79*a(n-4) - 138*a(n-5) - 3*a(n-6) + 100*a(n-7) - 18*a(n-8) - 20*a(n-9).

Empirical g.f.: 2*x*(126 - 841*x + 1356*x^2 + 1552*x^3 - 4886*x^4 + 609*x^5 + 3484*x^6 - 580*x^7 - 640*x^8) / ((1 - x)^2*(1 - 2*x)*(1 - 2*x - x^2)*(1 - 2*x - 2*x^2)*(1 - 2*x - 5*x^2)). - Colin Barker, Nov 20 2018

Example

Some solutions for n=4:
..0..0..0..0..0..1....0..1..0..1..0..0....1..0..1..0..1..0....1..0..0..0..0..0
..0..0..0..0..0..1....0..1..0..1..0..1....1..0..1..0..0..1....1..0..0..0..0..0
..0..0..0..0..1..0....0..1..0..1..1..0....1..0..1..0..1..0....1..0..0..0..0..1
..0..0..0..1..0..1....0..1..0..1..1..1....0..1..0..1..0..1....1..0..0..0..1..0
..0..0..0..0..1..0....0..1..0..1..1..1....0..0..1..0..1..0....1..0..0..0..1..0

Crossrefs

Column 5 of A250797.

Sequence in context: A254467 A242570 A046379 * A245858 A200884 A275316

Adjacent sequences: A250791 A250792 A250793 * A250795 A250796 A250797

Keyword

nonn

Author

R. H. Hardin, Nov 27 2014

Status

approved