A223191 - OEIS

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A223191

Number of nX4 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

50, 2500, 20016, 1133664, 41164952, 1615611339, 76015542500, 3621550793604

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Column 4 of A223195

LINKS

Table of n, a(n) for n=1..8.

EXAMPLE

Some solutions for n=3

..1..2..0..2....0..1..1..2....2..1..1..1....2..1..1..2....2..1..0..0

..0..0..0..0....0..0..1..1....0..1..0..1....1..1..0..0....0..0..0..0