A223176 Number of (n+2)X4 0..1 arrays with all rows and columns having a strictly positive second derivative in a quadratic least squares fit

0, 4, 40, 348, 1200, 16348, 94364, 524292, 2621432, 16536796, 84487288, 391704968, 2328596100, 11355881256, 62051315756, 313489275420, 1569528616420, 8055413661476

Offset

1,2

Links

Table of n, a(n) for n=1..18.

Example

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

Crossrefs

Column 2 of A223179.

Sequence in context: A121126 A145730 A069721 * A279574 A327675 A191681

Adjacent sequences: A223173 A223174 A223175 * A223177 A223178 A223179

Keyword

nonn,more

Author

R. H. Hardin, Mar 17 2013

Status

approved