A223494 Number of (n+2)X3 0..3 arrays with all rows having a nonnegative second derivative, and all and 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

5264, 172262, 7974566, 332428881, 12184078320, 451243568715, 17182947501552, 579662929049292, 21956435216459537

Offset

1,1

Comments

Column 3 of A223495

Links

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

Example

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

Crossrefs

Sequence in context: A204281 A251901 A274361 * A265985 A234994 A223341

Adjacent sequences: A223491 A223492 A223493 * A223495 A223496 A223497

Keyword

nonn

Author

R. H. Hardin Mar 20 2013

Status

approved