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Number of (n+2)X2 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

%I #4 Mar 25 2013 07:27:36

%S 9,25,169,729,3600,14161,63001,227529,1002001,4044121,16273156,

%T 62425801,265755204,1044840976,4209284641,16964020516,67776915600,

%U 271492060401,1096068706489,4316558882689,17448715791556,70160140107225

%N Number of (n+2)X2 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 Column 2 of A223652

%H R. H. Hardin, <a href="/A223646/b223646.txt">Table of n, a(n) for n = 1..45</a>

%e Some solutions for n=3

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Mar 25 2013