A223404 Number of nX2 0..3 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, 1296, 22500, 311364, 4519876, 71910400, 1131582321, 17402886400, 291627000625, 4505277934096, 70819882857025, 1143426767384836, 18481535149176100, 289271737594094161, 4654356085564331584

Offset

1,1

Comments

Column 2 of A223406

Links

R. H. Hardin, Table of n, a(n) for n = 1..43

Example

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

Crossrefs

Sequence in context: A207126 A207947 A308467 * A263566 A208140 A189266

Adjacent sequences: A223401 A223402 A223403 * A223405 A223406 A223407

Keyword

nonn

Author

R. H. Hardin Mar 20 2013

Status

approved