A250604 Number of (n+1)X(n+1) 0..1 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing x(i,j)-x(i-1,j) in the j direction

11, 64, 297, 1126, 3691, 10928, 30113, 78814, 198651, 486784, 1167337, 2752166, 6400283, 14716576, 33517185, 75712510, 169810507, 378463376, 838772201, 1849580902, 4059957771

Offset

1,1

Comments

Diagonal of A250611

Links

Table of n, a(n) for n=1..21.

Formula

Empirical: a(n) = 11*a(n-1) -52*a(n-2) +138*a(n-3) -225*a(n-4) +231*a(n-5) -146*a(n-6) +52*a(n-7) -8*a(n-8)

Example

Some solutions for n=6
..1..1..0..1..1..1..0....1..0..1..0..0..1..0....1..1..1..1..1..0..0
..1..1..0..1..1..1..0....1..0..1..0..0..1..0....1..1..1..1..1..0..0
..1..1..0..1..1..1..0....1..0..1..0..0..1..1....0..0..0..0..1..0..0
..1..1..0..1..1..1..0....1..0..1..0..0..1..1....0..0..0..0..1..0..0
..1..1..0..1..1..1..0....0..0..1..0..0..1..1....0..0..0..0..1..0..1
..0..1..0..1..1..1..0....0..0..1..0..0..1..1....0..0..0..0..1..0..1
..0..1..0..1..1..1..0....0..0..1..0..0..1..1....0..0..0..0..1..0..1

Crossrefs

Sequence in context: A357959 A285361 A237358 * A233164 A215445 A184055

Adjacent sequences: A250601 A250602 A250603 * A250605 A250606 A250607

Keyword

nonn

Author

R. H. Hardin, Nov 26 2014

Status

approved