A250774 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.

288, 514, 820, 1234, 1812, 2666, 4020, 6322, 10468, 18250, 33252, 62642, 120756, 236266, 466516, 926194, 1844676, 3680714, 7351812, 14692978, 29374228, 58735594, 117457140, 234898994, 469781412, 939544906, 1879070500, 3758120242

Offset

1,1

Links

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

Formula

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.

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

Example

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

Crossrefs

Row 6 of A250769.

Sequence in context: A244196 A280515 A061831 * A082994 A127350 A158253

Adjacent sequences: A250771 A250772 A250773 * A250775 A250776 A250777

Keyword

nonn

Author

R. H. Hardin, Nov 27 2014

Status

approved