A250767 Number of (n+1) X (6+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.

262, 410, 622, 962, 1558, 2666, 4798, 8978, 17254, 33722, 66574, 132194, 263350, 525578, 1049950, 2098610, 4195846, 8390234, 16778926, 33556226, 67110742, 134219690, 268437502, 536873042, 1073744038, 2147485946, 4294969678

Offset

1,1

Links

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

Formula

Empirical: a(n) = 4*a(n-1) - 5*a(n-2) + 2*a(n-3); a(n) = 64*2^(n-1) + 84*n + 114.

Empirical g.f.: 2*x*(131 - 319*x + 146*x^2) / ((1 - x)^2*(1 - 2*x)). - Colin Barker, Nov 18 2018

Example

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

Crossrefs

Column 6 of A250769.

Sequence in context: A345824 A045179 A264973 * A264972 A241877 A270752

Adjacent sequences: A250764 A250765 A250766 * A250768 A250769 A250770

Keyword

nonn

Author

R. H. Hardin, Nov 27 2014

Status

approved