A223497 Number of 4Xn 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

106, 11236, 172262, 20316988, 1634694162, 141426507841, 14653654917756, 1503865986455078, 147533896792235286

Offset

1,1

Comments

Row 2 of A223495

Links

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

Example

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

Crossrefs

Sequence in context: A234413 A083963 A166912 * A078281 A253622 A184208

Adjacent sequences: A223494 A223495 A223496 * A223498 A223499 A223500

Keyword

nonn

Author

R. H. Hardin Mar 20 2013

Status

approved