A223220 Number of nX1 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

2, 4, 5, 11, 19, 37, 68, 137, 261, 547, 1047, 2085, 4158, 8483, 16466, 33212, 66193, 131898, 263948, 527527, 1050219, 2116671, 4211442, 8401051, 16832288, 33765064, 67162966, 134559866, 269065487, 537669433, 1075891821, 2151469377, 4297450870

Offset

1,1

Comments

Column 1 of A223227

Links

R. H. Hardin, Table of n, a(n) for n = 1..122

Example

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

Crossrefs

Sequence in context: A192581 A095023 A049913 * A113058 A066145 A095022

Adjacent sequences: A223217 A223218 A223219 * A223221 A223222 A223223

Keyword

nonn

Author

R. H. Hardin Mar 18 2013

Status

approved