A223178 Number of (n+2)X6 0..1 arrays with all rows and columns having a strictly positive second derivative in a quadratic least squares fit

0, 348, 48316, 2485972, 76317552, 3171271500, 115722707546, 2886324889628, 88035882884812

Offset

1,2

Links

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

Example

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

Crossrefs

Column 4 of A223179.

Sequence in context: A054467 A230705 A230616 * A264326 A230609 A177174

Adjacent sequences: A223175 A223176 A223177 * A223179 A223180 A223181

Keyword

nonn,more

Author

R. H. Hardin, Mar 17 2013

Status

approved