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A223189
Number of nX2 0..2 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
1
9, 81, 256, 2500, 19044, 149769, 1306449, 11573604, 98962704, 945378009, 8103240324, 71267107681, 649113816976, 5922783740329, 51729783444964, 469159715409025, 4214751562369924, 37759790203876225, 340491211679997504
OFFSET
1,1
COMMENTS
Column 2 of A223195
LINKS
EXAMPLE
Some solutions for n=3
..0..2....2..2....2..2....0..2....2..2....2..2....0..2....2..1....0..1....1..0
..0..1....1..1....2..0....0..0....0..0....2..1....0..1....0..0....0..0....1..0
..0..2....1..0....2..0....2..0....1..1....2..0....1..2....1..2....1..1....2..1
CROSSREFS
Sequence in context: A207020 A207364 A207786 * A207781 A207165 A208009
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 18 2013
STATUS
approved