A250884 Number of (7+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

640002, 2304492, 5640102, 11227928, 19649066, 31484612, 47315662, 67723312, 93288658, 124592796, 162216822, 206741832, 258748922, 318819188, 387533726, 465473632, 553220002, 651353932, 760456518, 881108856, 1013892042, 1159387172

Offset

1,1

Comments

Row 7 of A250877

Links

Table of n, a(n) for n=1..22.

Formula

Empirical: a(n) = (290548/3)*n^3 + 254464*n^2 + (669458/3)*n + 65536

Example

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

Crossrefs

Sequence in context: A257187 A254987 A236996 * A190574 A210010 A179576

Adjacent sequences: A250881 A250882 A250883 * A250885 A250886 A250887

Keyword

nonn

Author

R. H. Hardin, Nov 28 2014

Status

approved