A223190 Number of nX3 0..2 arrays with all rows and columns having a nonnegative second derivative in a quadratic least squares fit, with one and two element arrays taken as having a zero second derivative

16, 256, 1138, 20016, 252544, 3407893, 52906752, 807057750, 12038960562, 208858564343, 3119961979390

Offset

1,1

Comments

Column 3 of A223195

Links

Table of n, a(n) for n=1..11.

Example

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

Crossrefs

Sequence in context: A207450 A208552 A267717 * A207469 A207521 A207920

Adjacent sequences: A223187 A223188 A223189 * A223191 A223192 A223193

Keyword

nonn

Author

R. H. Hardin Mar 18 2013

Status

approved