A223390 Number of (n+2)X3 0..2 arrays with all rows having a nonnegative second derivative, and all columns having a positive second derivative in a quadratic least squares fit, with one and two element arrays taken as having a zero second derivative

388, 5450, 120738, 2326103, 40102656, 663777212, 11304765020, 167298254365, 2855164209146

Offset

1,1

Comments

Column 3 of A223391

Links

Table of n, a(n) for n=1..9.

Example

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

Crossrefs

Sequence in context: A223193 A284147 A234178 * A200970 A104999 A139660

Adjacent sequences: A223387 A223388 A223389 * A223391 A223392 A223393

Keyword

nonn

Author

R. H. Hardin Mar 19 2013

Status

approved