A223223 Number of nX4 0..1 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

11, 121, 280, 3926, 26376, 251110, 2272864, 22449494, 215688364, 2635210346, 26127577834, 269923989830, 2987354654601, 35395852343115

Offset

1,1

Comments

Column 4 of A223227

Links

Table of n, a(n) for n=1..14.

Example

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

Crossrefs

Sequence in context: A228440 A015958 A014951 * A240942 A216131 A338784

Adjacent sequences: A223220 A223221 A223222 * A223224 A223225 A223226

Keyword

nonn

Author

R. H. Hardin Mar 18 2013

Status

approved