A250766 Number of (n+1) X (5+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.

133, 214, 344, 572, 996, 1812, 3412, 6580, 12884, 25460, 50580, 100788, 201172, 401908, 803348, 1606196, 3211860, 6423156, 12845716, 25690804, 51380948, 102761204, 205521684, 411042612, 822084436, 1644168052, 3288335252

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) = 49*2^(n-1) + 32*n + 52.

Empirical g.f.: x*(133 - 318*x + 153*x^2) / ((1 - x)^2*(1 - 2*x)). - Colin Barker, Nov 18 2018

Example

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

Crossrefs

Column 5 of A250769.

Sequence in context: A020446 A123997 A316630 * A254692 A050882 A146233

Adjacent sequences: A250763 A250764 A250765 * A250767 A250768 A250769

Keyword

nonn

Author

R. H. Hardin, Nov 27 2014

Status

approved