A222895 Number of n X n 0..2 arrays with successive rows and columns fitting to straight lines with strictly increasing slope, with a single point array taken as having zero slope

3, 31, 621, 230803, 129912903

Offset

1,1

Comments

Diagonal of A222896

Links

Table of n, a(n) for n=1..5.

Example

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

Crossrefs

Sequence in context: A380665 A319896 A370260 * A373754 A105293 A377746

Adjacent sequences: A222892 A222893 A222894 * A222896 A222897 A222898

Keyword

nonn

Author

R. H. Hardin Mar 08 2013

Status

approved