A250773 Number of (5+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.

144, 258, 418, 648, 996, 1558, 2526, 4284, 7600, 14010, 26586, 51472, 100956, 199614, 396598, 790212, 1577064, 3150370, 6296562, 12588504, 25171924, 50338278, 100670478, 201334348, 402661536, 805315338, 1610622346, 3221235744

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) = 24*2^(n-1) + 11*n^2 + 57*n + 52.

Empirical g.f.: 2*x*(72 - 231*x + 212*x^2 - 64*x^3) / ((1 - x)^3*(1 - 2*x)). - Colin Barker, Nov 19 2018

Example

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

Crossrefs

Row 5 of A250769.

Sequence in context: A316483 A064563 A008436 * A262245 A134341 A125841

Adjacent sequences: A250770 A250771 A250772 * A250774 A250775 A250776

Keyword

nonn

Author

R. H. Hardin, Nov 27 2014

Status

approved