A223495 T(n,k)=Number of (n+2)Xk 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, 784, 106, 5264, 11236, 466, 164650, 172262, 217156, 1970, 3726450, 20316988, 7974566, 3880900, 7904, 89957891, 1634694162, 4307975642, 332428881, 62473216, 31897, 2474370640, 141426507841, 1422650942236, 802504089833, 12184078320

Offset

1,1

Comments

Table starts

.....28.........784.........5264..........164650..........3726450

....106.......11236.......172262........20316988.......1634694162

....466......217156......7974566......4307975642....1422650942236

...1970.....3880900....332428881....802504089833.1045485381621951

...7904....62473216..12184078320.122450764432500

..31897..1017418609.451243568715

.130224.16958290176

.508551

Links

R. H. Hardin, Table of n, a(n) for n = 1..39

Example

Some solutions for n=1 k=4
..3..3..3..3....2..0..2..2....2..1..1..0....0..0..2..2....0..2..1..3
..2..0..2..1....0..0..0..0....0..0..0..0....0..0..0..1....1..1..0..2
..3..0..3..0....2..1..0..1....1..3..0..3....1..1..0..3....3..3..2..2

Crossrefs

Sequence in context: A291997 A171333 A097311 * A209228 A208505 A207878

Adjacent sequences: A223492 A223493 A223494 * A223496 A223497 A223498

Keyword

nonn,tabl

Author

R. H. Hardin Mar 20 2013

Status

approved