A223193 Number of nX6 0..2 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

387, 149769, 3407893, 1615611339, 386807892609, 103879396217927, 36214510060655577

Offset

1,1

Comments

Column 6 of A223195

Links

Table of n, a(n) for n=1..7.

Example

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

Crossrefs

Sequence in context: A038659 A232777 A259695 * A284147 A234178 A223390

Adjacent sequences: A223190 A223191 A223192 * A223194 A223195 A223196

Keyword

nonn

Author

R. H. Hardin Mar 18 2013

Status

approved