A223492 Number of (n+2)X1 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

28, 106, 466, 1970, 7904, 31897, 130224, 508551, 2071740, 8361761, 33294270, 132488646, 535901943, 2137571624, 8555879403, 34280993597, 137026129884, 548302259588, 2197308278858, 8759433440572, 35118744813397, 140658793309825

Offset

1,1

Comments

Column 1 of A223495

Links

R. H. Hardin, Table of n, a(n) for n = 1..81

Example

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

Crossrefs

Sequence in context: A201469 A010016 A256647 * A219857 A068196 A044279

Adjacent sequences: A223489 A223490 A223491 * A223493 A223494 A223495

Keyword

nonn

Author

R. H. Hardin Mar 20 2013

Status

approved