A250869 Number of (n+1)X(n+1) 0..3 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

90, 1456, 16262, 144248, 1097986, 7500960, 47315662, 280898512, 1590567658, 8673625464, 45876777622, 236629296200, 1195160833298, 5930230507888, 28981276937886, 139784115993376, 666528024959098, 3146266602049672

Offset

1,1

Comments

Diagonal of A250877

Links

R. H. Hardin, Table of n, a(n) for n = 1..35

Example

Some solutions for n=4
..2..2..2..2..2....2..2..2..2..2....0..0..0..0..0....2..2..2..2..2
..2..2..2..2..2....1..1..1..1..1....0..0..0..0..0....0..0..0..0..0
..1..2..2..2..2....0..0..0..1..1....0..0..1..1..1....3..3..3..3..3
..0..1..1..1..1....2..2..2..3..3....2..2..3..3..3....0..0..0..1..1
..1..3..3..3..3....2..2..2..3..3....0..0..1..3..3....1..1..1..2..3

Crossrefs

Sequence in context: A179800 A133350 A279438 * A234983 A166817 A166799

Adjacent sequences: A250866 A250867 A250868 * A250870 A250871 A250872

Keyword

nonn

Author

R. H. Hardin, Nov 28 2014

Status

approved