login
A223191
Number of nX4 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
0
50, 2500, 20016, 1133664, 41164952, 1615611339, 76015542500, 3621550793604
OFFSET
1,1
COMMENTS
Column 4 of A223195
EXAMPLE
Some solutions for n=3
..1..2..0..2....0..1..1..2....2..1..1..1....2..1..1..2....2..1..0..0
..0..0..0..0....0..0..1..1....0..1..0..1....1..1..0..0....0..0..0..0
..2..2..0..0....2..1..1..1....1..1..1..1....0..1..0..2....2..0..0..0
CROSSREFS
Sequence in context: A218753 A120998 A267061 * A223807 A223757 A223845
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 18 2013
STATUS
approved