%I #3 Mar 25 2013 07:31:38
%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
