|
|
A223219
|
|
Number of n X n 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
|
|
0
|
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
|
|
LINKS
|
|
|
EXAMPLE
|
Some solutions for n=3
..1..0..1....1..0..1....0..0..0....1..0..1....0..0..1....1..0..0....1..1..1
..1..0..0....0..0..1....0..0..0....1..0..0....0..0..0....0..0..0....1..0..0
..1..0..0....0..0..1....0..0..1....1..0..1....1..0..1....1..1..1....1..0..1
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|