A223647 Number of (n+2)X3 0..1 arrays with all rows having a nonnegative second derivative, and all and columns having a positive second derivative in a quadratic least squares fit, with one and two element arrays taken as having a zero second derivative

9, 43, 343, 1973, 10425, 64669, 347013, 1639675, 8731185, 47326725, 233731602, 1110256634, 5956720086, 29392316077, 153244540299, 763311486416, 3803535544870, 19110083922981, 96175235890299, 476447020677810

Offset

1,1

Comments

Column 3 of A223652

Links

R. H. Hardin, Table of n, a(n) for n = 1..21

Example

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

Crossrefs

Sequence in context: A110125 A221751 A275793 * A034194 A075206 A161457

Adjacent sequences: A223644 A223645 A223646 * A223648 A223649 A223650

Keyword

nonn

Author

R. H. Hardin Mar 25 2013

Status

approved