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A223645 Number of (n+2)X1 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 1
3, 5, 13, 27, 60, 119, 251, 477, 1001, 2011, 4034, 7901, 16302, 32324, 64879, 130246, 260340, 521049, 1046933, 2077633, 4177166, 8376165, 16722144, 33343800, 67054762, 133875590, 267805425, 536072391, 1071591827, 2143497919, 4292483722 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 1 of A223652

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..120

EXAMPLE

All solutions for n=3

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

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

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

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

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

CROSSREFS

Sequence in context: A289533 A288827 A084173 * A190570 A337860 A000631

Adjacent sequences:  A223642 A223643 A223644 * A223646 A223647 A223648

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 25 2013

STATUS

approved

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Last modified December 5 05:57 EST 2021. Contains 349531 sequences. (Running on oeis4.)