%I #3 Mar 25 2013 07:33:21
%S 60,3600,10425,1059839,24559913,1119629805,47882329200,2061491256869,
%T 95329202955957,6980023496929171,335311367775542739,
%U 17119067750905601475,1054799368422675063804,74856492204365399292957
%N Number of 7Xn 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 5 of A223652
%e Some solutions for n=3
%e ..0..0..1....1..1..1....1..1..1....1..1..1....0..0..1....1..0..1....1..0..1
%e ..0..0..1....0..0..1....1..0..1....0..0..0....1..0..1....0..0..0....1..1..1
%e ..0..0..0....0..0..0....0..0..1....1..0..0....1..1..1....0..0..1....0..0..0
%e ..0..0..0....0..0..1....0..0..0....1..1..1....0..0..1....0..0..1....0..0..0
%e ..1..0..0....1..0..0....0..0..1....0..0..1....0..0..0....1..0..0....1..0..0
%e ..1..0..0....0..0..1....0..0..0....1..1..1....0..0..0....0..0..0....0..0..0
%e ..1..1..1....0..0..0....1..0..1....1..0..1....1..1..1....1..1..1....1..1..1
%K nonn
%O 1,1
%A _R. H. Hardin_ Mar 25 2013
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