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A223656 Number of 6Xn 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

%I

%S 27,729,1973,78213,1044311,22982345,502081983,9622736121,218268103915,

%T 6831466723781,157202982490683,3596007897529929

%N Number of 6Xn 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

%C Row 4 of A223652

%e Some solutions for n=3

%e ..1..1..1....1..1..1....1..0..1....1..0..1....1..1..1....1..1..1....0..0..1

%e ..0..0..1....1..0..0....0..0..0....1..1..1....1..0..0....0..0..0....0..0..1

%e ..1..0..0....1..0..0....1..0..0....0..0..1....1..0..1....0..0..0....0..0..0

%e ..0..0..1....1..0..0....1..0..1....1..0..0....1..1..1....0..0..1....1..0..1

%e ..0..0..1....0..0..0....1..0..0....1..0..0....0..0..1....1..0..0....0..0..0

%e ..1..0..1....1..0..0....1..1..1....1..1..1....1..1..1....1..0..1....1..1..1

%K nonn

%O 1,1

%A _R. H. Hardin_ Mar 25 2013

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Last modified January 21 14:37 EST 2022. Contains 350479 sequences. (Running on oeis4.)