A223156 Number of (n+2)X4 0..2 arrays with all rows and columns having a strictly positive second derivative in a quadratic least squares fit.

989, 25929, 1328305, 55977857, 1853983303, 63763662879, 2163492588961

Offset

1,1

Comments

Column 2 of A223157

Links

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

Example

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

Crossrefs

Sequence in context: A232844 A057668 A217719 * A087702 A224565 A341604

Adjacent sequences: A223153 A223154 A223155 * A223157 A223158 A223159

Keyword

nonn

Author

R. H. Hardin, Mar 16 2013

Status

approved