A250996 Number of (2+1)X(n+1) 0..2 arrays with nondecreasing min(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

158, 872, 4007, 16993, 67409, 255502, 934786, 3328627, 11598747, 39713993, 134023188, 446828435, 1474417169, 4822285168, 15651307633, 50458460322, 161715555989, 515580776806, 1636125457220, 5170388337278, 16277908434300

Offset

1,1

Comments

Row 2 of A250994

Links

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

Formula

Empirical: a(n) = 9*a(n-1) -23*a(n-2) -12*a(n-3) +120*a(n-4) -72*a(n-5) -213*a(n-6) +197*a(n-7) +179*a(n-8) -186*a(n-9) -81*a(n-10) +75*a(n-11) +22*a(n-12) -11*a(n-13) -3*a(n-14)

Example

Some solutions for n=4
..1..0..2..0..0....0..2..1..1..1....1..1..1..0..1....2..0..0..2..0
..1..0..2..0..2....0..2..2..2..2....1..2..2..1..0....0..2..2..0..2
..1..1..0..2..0....0..2..2..2..2....1..2..2..2..1....0..2..2..1..0

Crossrefs

Sequence in context: A189813 A270791 A180096 * A280483 A252359 A159418

Adjacent sequences: A250993 A250994 A250995 * A250997 A250998 A250999

Keyword

nonn

Author

R. H. Hardin, Nov 29 2014

Status

approved