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 A223654 Number of 4Xn 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 5,25,43,229,799,3237,16975,58813,262975,1273157,6142655,26877117,

%T 132748947,716258257,3072240791,15826485913,73962438259,366204124645,

%U 1830090585655,8942164068501,44436414147403,225094702418657

%N Number of 4Xn 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 2 of A223652

%e Some solutions for n=3

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Mar 25 2013

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Last modified December 5 06:12 EST 2021. Contains 349532 sequences. (Running on oeis4.)