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A223648 Number of (n+2)X4 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 0
35, 229, 5751, 78213, 1059839, 13505813, 172509399, 1684095249, 20632590041, 242227127509, 2638617033260, 26781324092906 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A223652

LINKS

Table of n, a(n) for n=1..12.

EXAMPLE

Some solutions for n=3

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

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

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

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

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

CROSSREFS

Sequence in context: A195968 A104474 A171471 * A219474 A220208 A068722

Adjacent sequences:  A223645 A223646 A223647 * A223649 A223650 A223651

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 25 2013

STATUS

approved

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Last modified April 9 17:09 EDT 2020. Contains 333361 sequences. (Running on oeis4.)